So central was this emphasis on the Messiahship of Jesus that within a few years ‘Christ’ (the Greek for Messiah) had ceased to designate Jesus’s function and had come to be a sort of surname. Now all this was peculiarly offensive to the Jew. It was not easy to think of a carpenter-teacher as the summit of Israel’s development. It was not easy to think of someone so recent as embodying a wisdom greater than that of Moses long ago. It was not easy to believe that an unordained rabbi who often came into conflict with the official exponents of the Torah could be the divinely authenticated teacher of Israel. This was why in his lifetime so few of the religious leaders had any faith in him. But, after his execution, it was not merely difficult, it was preposterous to think of him as Messiah. By definition the Messiah was a deliverer, a conqueror….sinners would be expelled, pride rebuked, and Israel’s glory enhanced. But the political side of the Messiah’s work was primary. So long as God’s Holy Land languished under the domination of a foreign yoke, God himself was affronted every day. Deliverance must include political independence. And this Jesus manifestly failed to bring. His death upon the cross marked him out as a blatant failure, so far as any claim to Messiahship was concerned. So far from conquering, he was conquered. Why follow such a man?
Worse still, this worship of a crucified Messiah was distinctly blasphemous. the Old Testament made it perfectly plain that anyone hanged on a stake was resting under the curse of God. How could God’s Chosen One possibly have been exposed in the place of cursing? We know this constituted an almost insuperable problem to the Jew. Time and again in the Acts, and again in the letters of both Paul and Peter it is referred to: with good reason. Both of them had found the doctrine of a crucified Messiah a tremendous stumbling-block, until they came to understand its depth of meaning. The problem persisted for most Jews….
It would not have been so bad if Christians had contented themselves with asserting that Jesus was the Messiah. But they went much further. The earliest baptismal confession that we can trace is the short assertion that ‘Jesus is Lord’. It must be remembered that ‘Lord’ was the particular name for God in the Old Testament: in the LXX it translates Adonai. There could be no mistake about the matter….Is it any wonder that the Jews thought Christians were preaching a second God? How could they, in their pure monotheism, have any truck with such a blasphemy?
Michael Green, Evangelism in the Early Church, p. 33-35.