Hebrew for ‘anointed one’, who will be a saviour of the people, and used in OT of both kings and priests, especially of David and his successors, but also of Cyrus (Isa. 45: 1). In the prophets a future king of eschatological hope is expected to reign with justice and in peace (Isa. 11: 1–5), but the term ‘Messiah’ is not itself found in this sense in the prophets. The Dead Sea scrolls refer to the future coming of two anointed figures, one regal and one priestly, in the tradition of Melchizedek (Ps. 110: 4; Heb. 7: 1), who combined both functions in his person. In the Similitudes of Enoch (Enoch 37–71), from the middle of the 1st cent. CE, there is a Messiah who is also the heavenly Son of Man so that the widespread interest in a Davidic Messiah were both superhuman and transcendent features as well as earthly traits. So the fundamental reference is to God intervening in human history by sending his representative (though characteristic of Zealots was an emphasis on the sole rule of God and of human incapacity), and Christian readers discovered hints in the OT (e.g. Ps. 22: 6–8) that this person would have to suffer.
In the NT the Hebrew ‘Messiah’ becomes the Greek ‘Christos’, but references in the synoptics to Jesus as Messiah are scarce (Matt. 27: 17, 22); this rarity seems to reflect the known tradition of Jesus' reluctance to use such a title of himself, though the entry into Jerusalem (Mark 11: 1–10) and the Cleansing of the Temple (Mark 11: 15–19) suggest the notions of delivering his people, as prophesied by Malachi (3: 1). When Jesus was called Christ by Peter, he was rebuked (Mark 8: 29) and told to keep silent about it. Only at the trial did Jesus reply to the high priest's questions about Messiahship in the affirmative (Mark 14: 61 f.) and in Matt. (26: 64) this is modified to mean ‘you are right’—an assent to the question in a form in which Jesus minimizes the importance of the statement about the present: he was, to be sure, the Messiah (he means); but in the near future he would receive a position which would establish his Messianic dignity beyond doubt ‘at the right hand of God’—an utterance of blasphemy needing no further corroborative evidence in court. Similarly, the reply of Jesus to Pilate (Matt. 27: 11) is an admission of Messiahship but without explanation or justification—except in John (18: 36—‘my kingdom is not from this world’).
When the Church became predominantly Gentile, ‘Christ’ lost its original significance of Messiah, anointed one. Gentiles were not much interested in a Messiah who would restore the kingdom to Israel, so Christos became used as an adjective (perhaps confused with Chrestos, pronounced in the same way, meaning ‘good’) to describe Jesus. Then Christos became a proper name on its own account. Even Paul, Jew though he was, was beginning to use ‘Christ’ as a substitute for Jesus, or combined with it.