Well, there is probably one good reason people have such strong faith. I've had spiritual experiences. Now I don't attribute these experiences to a God, but have no doubt that we have a spiritual form. Believing as I do, I will never be one to deny that the Gods exist. I just don't believe in or worship any particular God. From my experience, it's easy to understand that people hear the word of a religion, be it Christianity, Islam, pagan, or whatever, and understand why they have a strong faith. I am in no position to say they are wrong.