If indeed the Gospel of Matthew was written in Greek, then Matthew simply wrote the Greek word Χριστοῦ (pronounced [khrē-stoo']), which is the genitive of Χριστός (pronounced [khrē-stos']).
Βίβλος γενέσεως Ἰησοῦ Χριστοῦ, υἱοῦ Δαβὶδ, υἱοῦ Ἀβραάμ
Declension Paradigm of the Greek Word χριστός
Nominative, singular number: χριστός
Nominative, plural number: χριστοί
Genitive, singular number: χριστοῦ
Genitive, plural number: χριστῶν
Dative, singular number: χριστῷ
Dative, plural number: χριστοῖς
Accusative, singular number: χριστόν
Accusative, plural number: χριστούς
The Greek word χριστός occurs countless times in the Septuagint. It is an adjective, and its literal English translation is "anointed." It can be used as a substantive with the meaning of "anointed (one)." This appears to be the sense of the word in expressions such as Ἰησοῦς Χριστός, or in English, "Jesus, [the] anointed [one]."
The English word "messiah" is simply a loanword carried over into English.
First, the original word is the Hebrew word מָשִׁיחַ (English transliteration: mashiach). This is an adjective which literally translates into English as "anointed." This word may likewise be used substantively as a noun, meaning "anointed (one)."
Translation of the Hebrew Word מָשִׁיחַ
The Hebrew word מָשִׁיחַ is translated into Greek as χριστός (e.g., LXX of 1 Sam. 16:6). It is translated into Latin as unctus (cp. Vulgate of Lev. 4:3). Each of these translations likewise means "anointed" when translated into English.
Translation process: [Hebrew] מָשִׁיחַ -> [Greek] χριστός -> [Latin] unctus -> [English] anointed.
Transliteration of the Hebrew Word מָשִׁיחַ
There are a few occasions where מָשִׁיחַ is not translated, but instead, it is transliterated into these languages.
For example, in John 1:41, it is written,
εὑρίσκει οὗτος πρῶτος τὸν ἀδελφὸν τὸν ἴδιον Σίμωνα καὶ λέγει αὐτῷ Εὑρήκαμεν τὸν Μεσσίαν ὅ ἐστιν μεθερμηνευόμενον ὅ Χριστός
The Greek word Μεσσίαν is the accusative declension of Μεσσίας. The Greek word Μεσσίας is actually a Greek transliteration of the Hebrew word מָשִׁיחַ. Koine Greek lacked the phonemes /ħ/ (represented by the Hebrew letter ח) and /ʃ/ (represented by the Hebrew letter שׁ); therefore, the Hebrew letter ח was not transliterated into Greek, and the Hebrew letter שׁ was transliterated as the digraph σσ.
In his Vulgate, Jerome transliterates the Greek word Μεσσίας by the Latin transliteration messias (cp. Vulgate of John 1:41), which is phonetically equivalent to the Greek word Μεσσίας.
Transliteration process: [Hebrew] מָשִׁיחַ -> [Greek] Μεσσίας -> [Latin] Messias -> [English] Messiah.
The Significance of Χριστός
When individuals were "anointed" in the Hebrew Tanakh, they were anointed with a special oil known as שֶׁמֶן הַמִּשְׁחָה (English transliteration: shemen ha-mishchah), or "the anointing oil" (cp. Exo. 29:7). Yeshu'a is referred to as ὀ χριστός (lit. "the anointed one"), yet we never read anything in the New Testament about him being anointed with actual oil. Why then is he referred to as χριστός?
In Acts 10:38, Luke writes,
How God anointed Yeshu'a from Nazaret with the Holy Spirit and with power, who went about doing good, and healing all that were oppressed of the devil, for God was with him.
Luke states that God the Father anointed Yeshu'a with the Holy Spirit (cp. Matt. 3:16; Mark 1:10; Luke 3:22; John 1:32). Compare this with Psalms 45:7, in which it is written,
You loved righteousness and hated wickedness. Therefore, O' God, your God anointed you with the oil of gladness more than your brothers."
The "oil of gladness" is the Holy Spirit which Yeshu'a, who here is referred to as "God" (the vocative "O' God"), was anointed with by his God (the Father), even more than his brothers, for regarding Yeshu'a, it is written (John 3:34),
For he whom God has sent speaks the words of God, for God has not given the Spirit by measure.
In summary, the Greek word Χριστός is a substantive adjective, meaning "the anointed one," and could (and perhaps, should) certainly be translated as such in the New Testament. It signifies that Yeshu'a was anointed with the Holy Spirit more than his brothers, hence he is the anointed one par excellence. In addition, based on the prophecy of Psalms 45:7, Χριστός alludes to the divinity and humanity of Yeshu'a, for not only is he God (vocative "O' God"), but also man ("Your God" implies that he has a God).
In De Civitate Dei ("On the City of God"), Book XVII, Ch. XVI, St. Augustine wrote,
Quis non hic Christum, quem praedicamus et in quem credimus, quamlibet sit tardus, agnoscat, cum audiat Deum, cuius sedes est in saecula saeculorum, et unctum a Deo, utique sicut unguit Deus, non uisibili, sed spiritalli atque intellegibili chrismate? Quis enim tam rudis est in hac religione uel tam surdus aduersus eius famam longe lateque diffusam, ut Christum a chrismate, hoc est ab unctione appellatum esse non nouerit?
which is translated as,
Who is there, no matter how slow, but must here recognize Christ whom we preach, and in whom we believe, if he hears that He is God, whose throne is for ever and ever, and that He is anointed by God, as God indeed anoints, not with a visible, but with a spiritual and intelligible chrism? For who is so untaught in this religion, or so deaf to its far and wide spread fame, as not to know that Christ is named from this chrism, that is, from this anointing?
| English | Latin |
Just before this quotation, St. Augustine quoted Psalms 45:1-9.