It is hard to believe in God if God is not defined (who, what, where, when, how).
Yet, billions believe in God.
Can millions be wrong?
Apparently, everyone thought that Noah was wrong when he built an ark in the middle of a desert, yet the flood proved Noah to be correct. This means that the masses of people (perhaps billions) could be wrong, as well.
If we believe what the majority believes, we'd have to believe that a lynch mob is correct.
The true test of our character is to stick to our beliefs, no matter how much peer pressure we feel.
I knew someone that everyone thought was nuts. But she was entitled to her opinion. Unfortunately, she died jumping off of a cliff (she said that she would survive). But she stuck to her beliefs to the bitter end, and you have to admire that. Perhaps we could write that on her tombstone?