"Now the Word became flesh and took up residence among us. We saw his glory – the glory of the one and only, full of grace and truth, who came from the Father. . . . No one has ever seen God. The only one, himself God [μονογενὴς θεός], who is in closest fellowship with the Father, has made God known" (John 1:14 and 18 NET Bible, my emphasis).
The word begotten, as the NET Bible's translation, above, implies, is perhaps an unfortunate rendering of the Greek word monogenes (μονογενὴς). One of my earliest memories from my upbringing in a conservative Christian denomination is the word begat, a variant of begotten, as in
"And Terah begat Abraham, and Abraham begat Isaac, and Isaac begat Jacob, and Jacob begat . . .," ad infinitum.
Where would genealogies be without a host of begats?!
To beget, of course, means "to become the father of" in the normal way; namely, the husband contributes his seed, the woman contributes her egg, the seed fertilizes the egg, and a human being is created and then "knit, or woven, together" in the womb of the mother-to-be (see Psalm 139:13 ff.). Nine months later, a baby is born.
The "begetting" of Jesus, however, did not proceed in the normal way. As S. Michael Houdmann observed,
"So what does monogenes mean? According to the Greek-English Lexicon of the New Testament and Other Early Christian Literature (BAGD, 3rd Edition), monogenes has two primary definitions. The first definition is 'pertaining to being the only one of its kind within a specific relationship.' This is its meaning in Hebrews 11:17 [where] the writer refers to Isaac as Abraham's 'only begotten son' (KJV). Abraham had more than one son, but Isaac was the only son he had by Sarah and the only son of the covenant. Therefore, it is the uniqueness of Isaac among the other sons that allows for the use of monogenes in that context." (Note: my emphasis.)
"The second definition is 'pertaining to being the only one of its kind or class, unique in kind.' This is the meaning that is implied in John 3:16 (see also John 1:14, 18; 3:18; 1 John 4:9). John was primarily concerned with demonstrating that Jesus is the Son of God (John 20:31), and he uses monogenes to highlight Jesus as uniquely God's Son—sharing the same divine nature as God—as opposed to believers who are God's sons and daughters by adoption (Ephesians 1:5). Jesus is God’s 'one and only' Son." (Note: my emphasis.)
From the perspective of John the Evangelist, both definitions (i.e., unique within a specific relationship, and unique in class or kind) applied to Jesus Christ. A Latin phrase which perhaps provides an excellent synonym for monogenes is sui generis, which means one of a kind, unique, singular.
In His relationship to the Father, the Word is utterly unique. Just as Isaac, the child of promise, was utterly unique (though Abraham had other offspring), so also the Word of God was uniquely the child of promise. Regarding the miraculous birth of Isaac, God appeared to Abraham in a vision, promising him a great reward. That reward was an heir,
"one who will come forth from your own body [, Abram]" (Genesis 15:4 ff.).
To ratify this promise, or covenant, God instructed Abram to shed the blood of animals (viz., a heifer, a goat, a ram, a turtledove, and a pigeon). While Abram slept the sleep of death, as it were, "a smoking oven and a flaming torch passed between" the animal sacrifices, and God pledged not only innumerable descendants to Abram, but also real estate, a land "from the river of Egypt as far as the great river, the river Euphrates" (ibid., vv. 9-21).
Regarding the Word becoming flesh, the promise which God fulfilled was made not in time but in eternity past within the eternal counsels of God, the same God
"who worketh all things after the counsel of his own will" (Ephesians 1:11 KJV).
The Word who became a flesh-and-blood human being was unique not only in His relationship to His Father, but He was also unique by being both the Son of God and the Son of Man in one person. Theologians call the oneness of the human and the divine in Jesus the hypostatic union. In short, the Word was the God-Man, the One in whom
". . . all the fullness of Deity dwells in bodily form" (Colossians 2:9).
". . . it was the Father's good pleasure for all the fullness to dwell in Him, and through Him to reconcile all things to Himself, having made peace through the blood of His cross; through Him . . . whether things on earth or things in heaven" (Colossians 1:19-20).
That the very essence of God would reside in a human being was made possible because the child of promise (the "seed of the woman" in Genesis 3:15) who was born to the virgin Mary was conceived by the Holy Spirit (Matthew 1:18 and 20; Luke 1:35). Being both fully God and fully man, Jesus could then become the perfect sacrifice for the sins of humankind, the One whom John identified as the
"Lamb of God who taketh away the sins of the world" (1:29 and 36).
The uniqueness of the identity of Jesus of Nazareth comprises the foundation of Christian theology. Conservative Christians down through the centuries have insisted, even at the cost of their lives, that Jesus was and always will be "the one and only" Son of God. The Nicene Creed (with scripture references) states this bedrock confession as follows:
[We believe in ] . . . in ONE Lord Jesus Christ, (Acts 11:17)
the Son of God, (Mathew 14:33; 16:16)
the Only-Begotten, (John 1:18; 3:16)
Begotten of the Father before all ages. (John 1:2)
Light of Light; (Psalm 27:1; John 8:12; Matthew 17:2,5)
True God of True God; (John 17:1-5)
Begotten, not made; (John 1:18)
of one essence with the Father (John 10:30)
by whom all things were made; (Hebrews 1:1-2)
Who for us men and for our salvation (1Timothy 2:4-5)
came down from Heaven, (John 6:33,35)
and was incarnate of the Holy Spirit and the Virgin Mary, (Luke 1:35)
and became man. (John 1:14)
In conclusion, the answer to the question "Did Jesus have a beginning?" is both yes and no. As God's "one and only," no, Jesus is eternally God the Son. As Yeshua, the son of the virgin Mary, yes, Jesus "became flesh and took up residence with us" (John 1:14). Moreover, in becoming a human being, Jesus made God known to us. In other words, Jesus was literally the exegesis of the very person of God to a world of fallen humanity, whom God loves dearly (John 3:16).
Read more: http://www.gotquestions.org/only-begotten-son.html#ixzz318n2PlPo