One can study this principle in a child; a child is born with faith. When you say, "This is water; this is bread; this is father; this is mother," the child does not refuse, the child does not say, "This is not so." The child at once takes it that it is so. It is afterwards that doubts begin to come, when the infant is grown up and hears a story and says, "But is it real?" Then doubts begin. Very often worldly knowledge gives more and more doubts; the experiences of worldly life make one doubt more and more. And when doubt becomes predominant in a person's nature, then he doubts everything and everyone.