You know, there is something called Christian Apologetics which is basically a study of the Bible in light of science and history.
I cannot speak for every religeon but there are some evidences for the Bible being true in many regards. There are quite an amount of videos, articles, essays and books on the matter. The belief in a God, in that regard, is not completely irrational.
Of course, to discuss Apologetics is to open a whole new can of worms. Im just saying this for the sake of discusion.