What does John 1:4 mean?

Question

In him was life, and that life was the light of all mankind. (NIV)

In context, the verse appears to be talking about the pre-incarnate Christ (this is in the section that begins "in the beginning" (1:1) and comes before it talks about any other time points "There was a man sent from God whose name was John." (1:6)).

The passage doesn't say that he was life, it says that "in him was life"

• What does it mean to say that the pre-incarnate Christ contained life?
• What does it mean to say that the life that pre-incarnated Christ contained was light?
• and that it was "the light" specifically "of all mankind"?

Answer 1

The Psalmist declares of God, “For with You is the fountain of life, and in Your light, we shall see light”.¹ Philo wrote, “God is the cause of life”² and “the ever-flowing fountain of living”.³

To live (ζῆν) is to have life (ἔχειν ζωὴν). The apostle Paul said God “gives life to all”⁴ and “in Him we live, and move, and exist”.⁵

God alone is inherently immortal,⁶ for God alone is uncreated. All else, created, is not inherently immortal. Thus, it is said, “the Father has life in Himself”.⁷

God declared to Moses, אֶהְיֶה אֲשֶׁר אֶהְיֶה (ehyeh asher ehyeh) — “I am He who exists” — and declared His name to be יַהְוֶה (Yahveh) — “He causes to exist.”⁸

The eternal life possessed by Christians is given or granted to them, not inherent, hence “God has given us eternal life”.⁹ Moreover, this eternal life is in Christ.¹⁰

And just as (ὥσπερ) the Father has life in Himself, and is inherently immortal, likewise (οὕτως...καὶ) the Son has life in Himself.¹¹ The Father gives the Son to have life in himself by virtue of begetting the Son from Himself before time (in eternity). (It is impossible for any creature to have life in itself, nor can God give any creature life in itself.)

Charles Lee Irons writes,¹²

My argument was that this verse ascribes to the Son the divine property of having “life in oneself” or aseity (from the Latin terms a + se, that is, “from oneself”). This is not a property that can be ascribe to any creature, for a creature, by definition, has life or existence from the Creator, not from himself or itself. Therefore, if the Son has “life in himself,” and he has it in the very same way that the Father has it, then he must be ontologically divine and not a created being.

Dixon’s response is not well thought out insofar as he makes an argument that clearly does not work; in fact, it dissolves the verse into a self-contradiction. He points to the fact that the same verse states the Father “granted” this property of aseity to the Son. Dixon argues that if he was “granted” or “given” this property, then he did not have it before being granted it. Therefore, Dixon, argues, this verse can be used to support his view that the Son is not eternal and that there was a time when he did not have life or existence. However, I do not think he has thought this through. If it is true that the verb “granted” means that there was a time when he did not have it, then it would contradict the other element of the verse, which states that he has life “in himself.” If there was a time when the Son did not have life or existence, and then at a certain point he received it from the Father, thus causing the Son to be brought out of nonexistence into existence, then he does not have life “in himself,” but rather has it from God in the same way that all other created beings do. On this interpretation, John 5:26 becomes self-refuting.

The Son possesses the same inherent immortality, “life in himself” (ζωὴν ἐν ἑαυτῷ), that the Father possesses, since both the Son and the Father are God in nature.

Augustine wrote,¹³

And let him who can understand, in that which the Son says, “As the Father hath life in Himself, so hath He given to the Son to have life in Himself,” not that the Father gave life to the Son already existing without life, but that He so begat Him apart from time, that the life which the Father gave to the Son by begetting Him is co-eternal with the life of the Father who gave it:

Et qui potest intellegere in eo quod ait Filius: Sicut habet Pater vitam in semetipso, sic dedit Filio vitam habere in semetipso; non sine vita exsistenti iam Filio vitam Patrem dedisse, sed ita eum sine tempore genuisse, ut vita quam Pater Filio gignendo dedit, coaeterna sit vitae Patris qui dedit:

A son shares the same nature as his father. That is, “Like begets like”.¹⁴ Since Jesus is the only-begotten son of the Father, who came out of the Father,¹⁵ and the Father is God in nature, the Son is also God in nature.

2 John 1:9

Whoever transgresses and does not abide in the doctrine of Christ does not have God. He who abides in the doctrine of Christ, he has both the Father and the Son.

Hence, eternal life is knowing the Father and the Son.¹⁶

John 1:1

In the beginning was the Word, and the Word was with God, and the Word was God.

Jesus is “that eternal life which was with the Father, and was manifested to us”.¹⁷ Likewise, the Father “is the true God and eternal life”.¹⁸ Jesus is the very Light.¹⁹ Likewise, the Father is Light.²⁰

“In him was life” means that Jesus is the fountain of life; he is inherently immortal. And since Jesus is the fountain of life, and inherently immortal, he is God. Of not one creature can it be said that life is in it, or it has life in itself. Only God has life in Himself; life is in God alone. All else lives and exists in God.

D. A. Carson writes,²¹

It is because, like God, he has life-in-himself. God is self-existent; he is always ‘the living God’. Mere human beings are derived creatures; our life comes from God, and he can remove it as easily as he gave it. But to the Son, and to the Son alone, God has imparted life-in-himself. This cannot mean that the Son gained his prerogative only after the incarnation. The Prologue has already asserted of the pre-incarnated Word, ‘In him was life’ (1:4). The impartation of life-in-himself to the Son must be an act belonging to eternity, of a piece with the eternal Father/Son relationship, which itself of a piece with the relationship between the Word and God, a relationship that existed ‘in the beginning’ (1:1). That is why the Son himself can be proclaimed as ‘the eternal life, which was with the Father and has appeared to us‘ (1 Jn. 1:2). Many systematicians have tied this teaching to what they call ‘the eternal generation of the Son’.

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Footnotes

1 Psa. 36:9 2 “On the Creation” (De Opificio Mundi), § 30: «ζωῆς...θεὸς αἴτιος» 3 “On Flight and Finding” (De Fuga et Inventione), §198: «πηγὴ τοῦ ζῆν...ἀένναος» 4 Acts 17:25: «διδοὺς πάσιν ζωὴν» 5 Acts 17:28: «Ἐν αὐτῷ...ζῶμεν καὶ κινούμεθα καὶ ἐσμέν» 6 1 Tim. 6:16 7John 5:26: «ὁ πατὴρ ἔχει ζωὴν ἐν ἑαυτῷ» 8 יַהְוֶה (yahveh) is conjugated in binyan Hifʿil, 3rd person, masculine gender, singular number, imperfect tense, from the verb הָיָה (hayah). Coincidentally, this particular conjugation occurs nowhere else in the Bible, with good reason: no one else but God could be the subject of this verb, as only God causes to exist. 9 1 John 5:11 10 ibid.: “...and this life is in His Son”. 11 John 5:26 12 Irons, p. 57 13 English: p. 225; Latin: p. 1094 14 Gen. 5:3: “And Adam...begat a son in his own likeness, after his image”. This is also derived in Gen. 1–2 when creatures are described as bringing forth “after its kind” – Hebrew לְמִינָהּ or Greek (LXX) κατὰ γένος. In modern language, we express this by the phenomenon that creatures reproduce progeny of the same species. Coincidentally, in modern Hebrew, the word מִין is used for “species”. 15 John 8:42 16 John 17:3 17 1 John 1:2 18 1 John 5:20 19 John 1:9 20 1 John 1:5 21 Carson, pp. 256–257

References

Aurelius Augustinus Hipponensis. A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church. “On The Trinity”. Trans. Haddan, Arthur West. Ed. Schaff, Philip. Vol. 3. Buffalo: The Christian Literature Company, 1887. Aurelius Augustinus Hipponensis. Patrologiæ Cursus Completus: Series Prima. “De Trinitate”. Ed. Migne, Jacques Paul. Vol. 4. Petit-Montrouge: Imprimerie Catholique, 1843. Carson, D. A. The Gospel according to John. Grand Rapids: Eerdmans, 1991. Dixon, Danny André; Irons, Charles Lee; Smith, Dustin R. The Son of God: Three Views of the Identity of Jesus. Eugene: Wipf and Stock Publishers, 2015.

Answer 2

ἐν αὐτῷ ζωὴ ἦν, καὶ ἡ ζωὴ ἦν τὸ φῶς τῶν ἀνθρώπων· (John 1:4, NA28)

In him was life, and the life was the light of men. (John 1:4, ESV)

How to interpret this verse depends largely on whether you connect ὃ γέγονεν at the end of verse 3 to the rest of verse 3 or to verse 4. The poetic structure of the prolegomena would put ὃ γέγονεν with v4: What is the correct punctuation of John 1:3-4?. However, traditionally it has been placed with v3.

Some problems with ὃ γέγονεν going with verse 4:

That which as made in him was life and life was the light of men.

1. The previous verse context is all things that were created. All things created is more than life.

All things were made through him, and without him was not any thing made.

It just doesn't make sense in the context. It makes no connection.

2. Life is an attribute of God. He is the living God (אֱלֹהִ֨ים חַיִּ֜ים , Deut. 5:26; 1 Sam 17:26,36; Jer. 10:9;23:36).

3. Moreover, ζωή is never used with reference to mere creature life; its character is always heavenly and spiritual never physical. -- Lenski, R. C. H. (1961). The interpretation of St. John’s gospel (p. 39). Augsburg Publishing House.

4. In the prolegomena John uses ἦν to refer to that which already was from the beginning as opposed to that which was created, in which he used γίνομαι. Putting ὃ γέγονεν with v4 breaks this expression.

5. ὃ γέγονεν with v3 fits well in Hebrew:

הַכֹּל נִהְיָה עַל־יָדוֹ וּמִבַּלְעָדָיו לֹא נִהְיָה כָּל־אֲשֶׁר נִהְיָה׃ (John 1:3, Delitzsch)

This puts a limitation on everything. God did not become. Thus, the Word did not make God.

But what about the light of men, τὸ φῶς τῶν ἀνθρώπων? In Genesis 1 God created light, but this is the light of men. The term only occurs here in the Bible. This term appears to be closely related to the light of the world.

Again Jesus spoke to them, saying, “I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life. (John 8:12, ESV)

But Jesus’ statement seems to contradict this in Matthew.

You are the light of the world. A city set on a hill cannot be hidden. Nor do people light a lamp and put it under a basket, but on a stand, and it gives light to all in the house. In the same way, let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven. (Matt. 5:14–16, ESV)

Jesus qualification “As long as I am in the world,…” explains this seeming contradiction.

As long as I am in the world, I am the light of the world. (John 9:5, ESV)

This is the extent of the use of the light of the world in the Bible. The light of men in John 1:4 indicates that God’s plan of sending the Son to redeem the world was his eternal plan existing before the beginning of the world.

Answer 3

Note the large number of verbal parallels between John 1:1-5 and Gen 1:1-4;

• “in the beginning”,
• word/spoken,
• God,
• creation of all things,
• light,
• darkness, etc.

Thus, John 1:1-5 is directly alluding to Gen 1:1-4, the creation of this world. Thus, when John 1 says that the Word was God, and, the Word was the source of life, it means just that - the Word was involved in the creation of the world as explicitly stated by John 1:3. Therefore, this also means that the Word created the animals and plants, as well as humans.

Thus, the Word was life indeed. Several translations make this explicit:

• NLT: The Word gave life to everything that was created
• GNT: The Word was the source of life

Ellicott makes a similar comment:

(4) In him was life.—The creation, the calling into existence life in its varied forms, leads up to the source of this life. It is in the Word by original being, while of the highest creature made “in the image of God” we are told that God “breathed into his nostrils the breath of life, and man became a living soul” (Genesis 2:7).

“Life” has here no limitation, and is to be understood in its widest sense; the life of the body, even of organisms which we commonly think of as inanimate, the life of the soul, the life of the spirit; life in the present, so far as there is communion with the eternal source of life; life in the future, when the idea shall be realised and the communion be complete.

Next, the assertion that the Word was light, is also alluding to the main activity on Day #1 of creation week when God said, "Let there be light". This was before day #4 when the sun provided light. Thus, we find in Ps 27:1, that "The LORD is my Light" is an allusion to the same idea, coupled with Jesus' own declaration (John 8:12), "I am the Light of the World." (See also 1 John 1:5).

There can be little mistaking the rather obvious inference made explicit in John 1:1 that "The Word was God."

Answer 4

Summary
The meaning of the verse is Jesus is both life and light, two things which are inseparable. The main emphasis is looking forward to making children of God. This future outcome is presented as a continuation of Him through whom all things came into existence. The relevance of the past work is to show the one who had the ability to make all things continues to make all things, specifically children of God.

The Literary Structure
With respect to this verse 4, some believe the beginning completes the thought which begin in verse 3 and the next thought begins in the middle of the verse:

#1: ³ All things came into existence through him, and apart from him not even one thing came into existence. ⁴ What has come into existence by means of him was life.
#2: ⁴ And the life was the light of men. ⁵ And the light is shining in the darkness, but the darkness has not overpowered it. (NWT)

#1: ³ All things were made through him, and without him was not any thing made that was made.
#2: ⁴ In him was life, and the life was the light of men. ⁵ The light shines in the darkness, and the darkness has not overcome it. (ESV)

When the text is parsed as in the NWT ¹, in Him was life completes what has come into existence. The change in punctuation removes in Him was life making life and light independent of Him.

The original text lacked punctuation, but writers used other devices like structure to show where one thought ended and the next began. In his article Chiasmus: An Important Structural Device Commonly Found in Biblical Literature, Brad McCoy discusses chiasms, their use, and their exegetical significance. The Prologue is one example he gives showing how a chiastic structure functions to punctuate a passage: ²

A: The Word with God (1-2)  
 B: The Word's role in creation (3)  
  C: God's grace to mankind (4-5)  
   D: Witness of John the Baptist (6-8)  
    E: The Incarnation of the Word (9-11)  
     X: Saving faith in the Incarnate Word (12-13)  
    E': The Incarnation of the Word (14)  
   D': Witness of John the Baptist (15)  
  C': God's grace to mankind (16)  
 B': The Word's role in re-creation (17)  
A': The Word with God the Father (18)

McCoy summarizes three significant aspects of a composition using this device: ³

1. Delineate units of thought
2. Accentuate the main idea or theme the writer is concerned to convey to their readers
3. Compare and contrast the interplay between textually separated but thematically paired units of thought

The central theme in the Prologue is making children of God:

¹² But to all who did receive him, who believed in his name, he gave the right to become children of God, ¹³ who were born, not of blood nor of the will of the flesh nor of the will of man, but of God.

Becoming children of God is a result of receiving Him and believing in His name. Significantly, it is He who gives the authority to those who believe. In other words, it is accomplished by the Word who had the authority and ability to give those who believe that which they were not born with and otherwise would not have obtained.

An important aspect of the Prologue is the presence of the Word in each distinct thought:

A: The Word with God (1-2)  
 B: The Word's role in creation (3)  
  C: The Word is life and light (4-5)  
   D: John the Baptist gives witness to the Word (6-8)  
    E: The Word comes to His own (9-11)  
     X: The Word gives authority to those who believe (12-13)  
    E': The Word is made flesh (14)  
   D': John the Baptist gives witness to the Word (15)  
  C': The fulness of the Word gives grace (16)  
 B': Grace and truth come from the The Word (17)  
A': The Word returns and is with the Father (18)

Punctuating verses 3 and 4 as in the NWT removes the Word from the idea which follows and is contrary to the structure. It also implies life and light are not from the Word. This is at odds with the Word bringing all things into existence and being the integral component to making children of God. Therefore, the traditional punctuation is correct. Verse 4 begins the next thought with In Him was life and the life was the light of men.

The Grammatical Structure
The writer also employed grammar to show the complete thought. The composition is ἐν αὐτῷ ζωὴ ἦν καὶ ἡ ζωὴ ἦν τὸ φῶς τῶν ἀνθρώπων.

The grammatical device is the phrase ἡ ζωὴ ἦν τὸ φῶς which has two meanings:

And the life was the light of men (κα η ζωη ην το φως των ανθρωπων). Here the article with both ζωη and φως makes them interchangeable. "The light was the life of men" is also true.⁴

The writer composed a statement so that both in Him was life and the life was the light of men and in Him was life and the light was the life of men are true. The full meaning of the verse is:

in Him was life and the life was the light of men and
in Him was life and the light was the life of men

The life is the light of men and the light is the life of men. The first reading is a logical continuation of in Him was life.... The second reading is literally "behind the scenes." What is a grammatical possibility in the Prologue is developed as an explicit reality in the Gospel. When John reports Jesus saying I am the light of the world, it looks back to the Prologue, in Him was life and the light was the life of men.

Conclusion - Life and Light
John is affirming Jesus is both life and light and the inseparable connection between the two. The life in Him is life which is the light of men and He is the light which is the life of men.

Immediately after making this statement John makes two clarifying statements. First, he explains the role of John the Baptist as it relates to light:

⁶ There was a man sent from God, whose name was John. ⁷ He came as a witness, to bear witness about the light, that all might believe through him. ⁸ He was not the light, but came to bear witness about the light.

Unlike Matthew, Mark, and Luke, John focuses the Baptist's message on light. He is to bear witness about the light, Jesus, so that all might believe through Jesus. Importantly, the Baptist is not the light. He is simply a messenger of the light.

⁹ The true light, which gives light to everyone, was coming into the world.

The Baptist's role is further distinguished: Jesus is the true light. Jesus gives light to everyone. His light is the light of life just as His life is the life of light.

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<sub>1. NWT is the New World Translation produced by the Watch Tower Society, also know as Jehovah's Witnesses.
2. Brad McCoy, "Chiasmus: An Important Structural Device Commonly Found in Biblical Literature." p 29 Chafer Theological Seminary
3. McCoy pp.30-31
4. Robertson's Word Pictures in the New Testament</sub>

Answer 5

Yes, everything was made by Him, but man dying in darkness consummates in death. He needs life and the word of God that became flesh in the form of Jesus united to man's death, overcame sin that caused death, and brought up all out of the grave into the light of life.

Matthew 4:16

the people dwelling in darkness have seen a great light, and for those dwelling in the region and shadow of death, on them a light has dawned.

1 Peter 2:9

But you are a chosen people, a royal priesthood, a holy nation, a people for God's own possession, to proclaim the virtues of Him who called you out of darkness into His marvelous light.

Acts 13:47

For so hath the Lord commanded us, saying, I have set thee to be a light of the Gentiles, that thou shouldest be for salvation unto the ends of the earth.

Ephesians 5:8

For you were once darkness, but are now light in the Lord. Walk as children of light,

So in summary darkness and death go hand-in-hand, and light and life go hand-in-hand.

God always does everything through His word as He sends it forth to accomplish whatever He wants. At this point in time, the word became flesh with life and light to bring man out of darkness and death.

Isaiah 55:11

So shall my word be that goeth forth out of my mouth: it shall not return unto me void, but it shall accomplish that which I please, and it shall prosper in the thing whereto I sent it.

Answer 6

1. What does it mean to say that the pre-incarnate Christ contained life?

   The verse John 1:4 states that "in him was life." This is intrinsically related to the concept of "logos" (λόγον), which can be understood as the Word or the Verbum of God. In a broader context, "logos" represents the divine expression, the wisdom of God, the mind, and will of God made manifest. Therefore, to say that "in him was life" indicates that this Word, this Verbum of God (Christ), contained the very essence and source of life. Christ is the source and origin of life because He is the divine expression and, consequently, the source of life for all humanity.

   Considering the passages from Deuteronomy 4:9 and Deuteronomy 32:47, we perceive a connection between the importance of keeping and following the words of God (the "logos"). Just as these words were fundamental for the life and well-being of the people of Israel, the "logos" represented by Christ is fundamental for the eternal and spiritual life of all believers.

2. What does it mean to say that the life that pre-incarnate Christ contained was light?

   The verse John 1:4 continues to say that "the life was the light of men." Light is often symbolically used in the Scriptures to represent truth, knowledge, guidance, and the revelation of God. Again, this is linked to the concept of "logos." Christ, as the divine expression and the wisdom of God, is the light that illuminates the spiritual darkness of humanity.

   The light of Christ brings spiritual understanding, reveals the nature of God, guides people on the path of righteousness, and unveils the truth about life and purpose. In the cited passage of John 5:24, the idea that those who hear and believe in the Word of Christ have eternal life reinforces the association between "life" and "light" found in verse 1:4. The light of Christ brings spiritual and eternal life.

3. And that it was "the light" specifically "of all mankind"?

   By stating that the life contained in Christ was the light of all mankind, it is indicated that Christ was not a light restricted to a specific group or nation. He was the light that came to illuminate all human beings, regardless of their origin, culture, or position in society.

   This aligns with the concept that Christ came to be the Savior of all humanity, offering salvation and eternal life to all those who believe in Him, as expressed in John 5:24. The light of Christ is available to all human beings, inviting them to step out of spiritual darkness and receive eternal life through faith in Him.

These interpretations are rooted in the understanding of the terms "logos" and "life" in the biblical context, as well as in the analogies present in the Scriptures that help elucidate the meaning of the discussed concepts.

Answer 7

1. "In Him was life" = just as God the Father has life in Himself, so also He granted the Son-Logos to have life in Himself (John 5:26), and it is not that the Father could grant and could not, having chosen to grant, but He granted this possession of life to the Son by the very fact of begetting the Son, which He, the Father, does naturally and eternally and necessarily, therefore the Son possessing the fullness of Life in Himself does so just like the Father, and since this Life is one Life, then its equal possession manifests the equal divinity of the Father and the Son.

2. The Life was light in the sense that this Life implies the fullness of divine operations or energies, and those operations or energies can be considered and termed metaphorically as "light" dissipating a) the darkness of ignorance, because the knowledge and wisdom is also a divine energy; b) cleansing from a sinful inclination, because the purificatory operations and energies are also a part of this Life; c) enlightening the darkness of hatred and unforgiving, because love through which we can do so, is also one of the energies of God, and aspect of His life.

3. This "light", these divine operations are not relegated only to Jewish ethnicity, but are accessible to all humans. As the sunlight enlightens visibly all humans, brutes, plants and inanimate objects involuntarily, so the "light" the divine grace or operations are present and transform every human being, but already with their volition to co-act, co-operate with those operations and get divinized.

Answer 8

John 1:4 ASV

In him (the word) was life; and the life was the light of men.

The word, God's words and Jesus' words, are spirit and life (John 6:63) in that if we believe/know God's words we will have life John 17:3. 3:16.

Now when the word became flesh and was identified as Jesus, he pointed to his God as the source of his life. John 6:57. His life was caused by the Father, his God. John 17:3, 17, Revelation 3:12. The Prince of life was killed and was resurrected by his God. Acts 3:15. Thus, he could not be the God of the Living Mark 12:27 or the Living God Jeremiah 10:10.

"The light of all mankind".

Jesus personified light in the way he lived and taught, John 3:19. ‘Man shall not live on bread alone, but on every word that comes from the mouth of God.’” Matthew 4:4, His words are like a lamp, lighting and guiding the way of God’s servants in the darkness of this world. His word is a lamp for my feet, a light for my pathway. Psalm 119:105

The "Word" cannot be the creator as some claim it is. In one answer, it states "the Word was involved in the creation of the world as explicitly stated by John 1:3. Therefore, this also means that the Word created the animals and plants, as well as humans". "There can be little mistaking the rather obvious inference made explicit in John 1:1 that "The Word was God."

Notice that the sentence "the word was God" is used to conclude that Jesus is God without identifying the God that he was with as shown in John 1:1

Note that John 1:1 states "In the beginning was the Word, and the Word was with God, and the Word was God."

Some think that God is a multi-person God (3-in-1), where the term word refers only to Jesus, "God the Son, while God is the equivalent of the "God the Father, God the Son, and God the Holy Spirit".

Substituting the terms "word" and "God" in John 1:1 according to this multi-person God idea, we then have, in the beginning was God the Son, and God the Son was with God the Father, God the Son, and God the Holy Spirit. And God the Son was God the Father, God the Son, and God the Holy Spirit.

Postulating an idea that the verse does not convey shows the self-contradictory explanation of a multi-person God idea. There is no record from the bible that supports the idea of a Creator called Word or Jesus in the bible. Jesus himself ascribed creation to his God, not himself. Mark 13:19, Matthew 19:4, and Mark 10:6. The Father/YHWH is the only Creator. Malachi 2:10.

Answer 9

What does it mean to say that the pre-incarnate Christ contained life?

While most Bibles translate the passage as quoted in the question, there are a few other ways it has been translated:

• Common English Bible

  through the Word was life, and the life was the light for all people.

• Contemporary English Bible

  received its life from him, and his life gave light to everyone.

• New Life Version

  Life began by Him. His Life was the Light for men.

• New Living Translation

  The Word gave life to everything that was created, and his life brought light to everyone.

• New World Translation

  by means of him was life, and the life was the light of men.

While speaking with the people at the Temple, Jesus made the following statement: John 5:25, 26

²⁵ Most truly I say to you, the hour is coming, and it is now, when the dead will hear the voice of the Son of God, and those who have paid attention will live. ²⁶ For just as the Father has life in himself, so he has granted also to the Son to have life in himself.

Jesus recognized and acknowledged that Jehovah God is the creator of life. (Psalm 36:9; Revelation 4:11) The apostle John did the same and thus wrote verse 4.

But how does Jesus have life in him? Imagine the following: a light bulb cannot produce light on its own but requires electricity. Electricity doesn't jump into the bulb but requires a means to get to the bulb, hence the wiring. But where does the electricity come from? It comes from the company producing the electricity via different means. So Jehovah provides the means for life through the conduit, Jesus Christ.

Not only was Jesus the instrument by which Jehovah brought about creation itself (John 1:3, Colossians 1:16, 17), but by means of Jesus' ransom sacrifice mankind can attain eternal life. (John 3:16, 6:68, 69)

What does it mean to say that the life that pre-incarnated Christ contained was light?

Jesus applied the words found in Isaiah to himself

Isaiah 9:1, 2

¹ However, the gloom will not be as when the land had distress, as in former times when the land of Zebu·lun and the land of Naphta·li were treated with contempt. But at a later time He will cause it to be honored—the way by the sea, in the region of the Jordan, Galilee of the nations. ² The people who were walking in the darkness Have seen a great light. As for those dwelling in the land of deep shadow, Light has shone on them. [bold mine]

Isaiah 42:1, 6

¹ Look! My servant, whom I support! My chosen one, whom I have approved! I have put my spirit in him; He will bring justice to the nations. ... ⁶ “I, Jehovah, have called you in righteousness; I have taken hold of your hand. I will safeguard you and give you as a covenant for the people And as a light of the nations, [bold mine]

Isaiah 49:6

⁶ And he said: “It is not enough that you are my servant To raise up the tribes of Jacob And to bring back those who were preserved of Israel. I have also given you as a light of nations, So that my salvation may reach the ends of the earth.”

John 8:12

Then Jesus spoke again to them, saying: “I am the light of the world. Whoever follows me will by no means walk in darkness, but will possess the light of life.” [bold mine]

A lighthouse is a beacon for sailors to find their way back to port, especially during a storm. In a similar fashion, Jesus is the way to for mankind to find everlasting life. (John 14:6)

and that it was "the light" specifically "of all mankind"?

Note the following information from the article "How Should John's Gospel Affect You?" found in the Watchtower of May 1, 1982:

In Jn 1 verses three and four of the first chapter of his Gospel, John takes us into two of those key themes that are interwoven into the fabric of his inspired account by saying: “What has come into existence by means of him [the Word] was life, and the life was the light of men.” What does John convey by this statement? That the Word, or Christ, was God’s Chief Agent for communicating both life and light to mankind. (Acts 3:15) John continues by telling us that John the Baptizer arose to bear witness about “the true light that gives light to every sort of man.” (John 1:9) Yes, to every sort of man, because Christ did not come into the world just to be a Messiah for the Jews. He came for the benefit of all mankind, as he himself explained: “God loved the world [of mankind since Abel] so much that he gave his only-begotten Son [Christ, the Word], in order that everyone exercising faith in him might not be destroyed but have everlasting life.”​—John 3:16.

While Jesus' ministry was focused on providing salvation to the nation of Israel, the rest of the world could have that same salvation. (Acts 10:34, 35)

[All scripture quotations from the New World Translation of the Holy Scriptures (Study Edition)]