[wideawake]

I am going to guess that certain people think it is sacrilegious to say they know that God exists, feeling that His existence is properly a matter of faith, not knowledge.

I would guess that another group do not believe in God, but are members of a religious group for form's sake (pleasing their family) or because they sympathize with the moral code the religion promotes.

[stuartcr]

I asked, because it just sounded odd that there are people that follow a faith closely, but are uncertain if God exists. Then of course, there are those that are certain, but cannot offer any kind of universally acceptable proof, that doesn't require a similar belief.