Celsus, still expressing his opinion regarding the Jews, says: “It is not probable that they are in great favour with God, or are regarded by Him with more affection than others, or that angels are sent by Him to them alone, as if to them had been allotted some region of the blessed. For we may see both the people themselves, and the country of which they were deemed worthy.” We shall refute this, by remarking that it is evident that this nation was in great favour with God, from the fact that the God who presides over all things was called the God of the Hebrews, even by those who were aliens to our faith.
And because they were in favour with God, they were not abandoned by Him; but although few in number, they continued to enjoy the protection of the divine power, so that in the reign of Alexander of Macedon they sustained no injury from him, although they refused, on account of certain covenants and oaths, to take up arms against Darius. They say that on that occasion the Jewish high priest, clothed in his sacred robe, received obeisance from Alexander, who declared that he had beheld an individual arrayed in this fashion, who announced to him in his sleep that he was to be the subjugator of the whole of Asia. Accordingly, we Christians maintain that “it was the fortune of that people in a remarkable degree to enjoy God's favour, and to be loved by Him in a way different from others;” but that this economy of things and this divine favour were transferred to us, after Jesus had conveyed the power which had been manifested among the Jews to those who had become converts to Him from among the heathen.
And for this reason, although the Romans desired to perpetrate many atrocities against the Christians, in order to ensure their extermination, they were unsuccessful; for there was a divine hand which fought on their behalf, and whose desire it was that the word of God should spread from one corner of the land of Judea throughout the whole human race.
Source: Against Celsus (New Advent)