See, i've asked this question before, typical answers are:
"Because in my church i see miracles performed by my chosen god and never saw proof of any other god"
"Just because i do"
No, wait... I love this one:
Me: "if you were born in a muslim or atheist village, you would believe in allah or no god at all also"
They: "no, i wouldn't"
"why not?"
"jesus would show me the way"
I love to be an atheist
Flow -"The important is to pwn other ppl"