Strife and prejudice are powerful instruments in leading men to disregard even those things which are abundantly clear; so that they who have somehow become familiar with certain opinions, which have deeply imbued their minds, and stamped them with a certain character, will not give them up. For a man will abandon his habits in respect to other things, although it may be difficult for him to tear himself from them, more easily than he will surrender his opinions. Nay, even the former are not easily put aside by those who have become accustomed to them; and so neither houses, nor cities, nor villages, nor intimate acquaintances, are willingly forsaken when we are prejudiced in their favour.
This, therefore, was a reason why many of the Jews at that time disregarded the clear testimony of the prophecies, and miracles which Jesus wrought, and of the sufferings which He is related to have endured. And that human nature is thus affected, will be manifest to those who observe that those who have once been prejudiced in favour of the most contemptible and paltry traditions of their ancestors and fellow citizens, with difficulty lay them aside. For example, no one could easily persuade an Egyptian to despise what he had learned from his fathers, so as no longer to consider this or that irrational animal as a god, or not to guard against eating, even under the penalty of death, of the flesh of such an animal.
Now, if in carrying our examination of this subject to a considerable length, we have enumerated the points respecting Bethlehem, and the prophecy regarding it, we consider that we were obliged to do this, by way of defence against those who would assert that if the prophecies current among the Jews regarding Jesus were so clear as we represent them, why did they not at His coming give in their adhesion to His doctrine, and betake themselves to the better life pointed out by Him? Let no one, however, bring such a reproach against believers, since he may see that reasons of no light weight are assigned by those who have learned to state them, for their faith in Jesus.
Source: Against Celsus (New Advent)