To keep relatively on topic, I refuse to believe in god out of pride.

If god prefers good people, then I do not want someone rewarding me with infinite bliss when I die, because that would trivialise my works on earth. I would rather the good I do be out of the good I want to spread in the world. That is, of myself.

If god prefers only those people who believe in him, then I refuse to believe in him because he does not encourage truly good behaviour.

If god does pretty much anything else, I refuse to believe in him because he’s an arsehole.

Replace ‘god’ with [insert name of god/gods/deities/etc.] to cover all religions.