If I had a dollar for everytime I heard a religious person make one of these claims I'd be a wealthy man.
Theist: Who are you to question God?
Me: I'm not questioning God, I'm questioning you. Please learn the difference. God isn't the one claiming he exists. You are. I'm not having a conversation with God. I'm having a conversation with you.
Theist: Why do you hate God?
Me: I don't hate God, I just think you're claiming to know things you can't possibly know and have abilities that you don't actually have. We have a word for such behavior - it's called Arrogance.
Theist: You reject God because you're afraid / want to sin / etc.
Me: I'm not afraid of there being a God. Because if there is a God, I will continue treating people as best I can - as I already do. I value the well-being of sentient creatures regardless of the existence or nonexistence of deities. No God(s) necessary.
However, I do believe that you're the one who's afraid that their may be no God - as then you - and you alone- will be accountable for your actions. No grace - no pardoning - no blood sacrifices for eternal forgiveness. You will have to go to bed each night knowing that your actions, good or bad, will echo into the future. That you can no longer beg off responsibility to your fellow man by appealing to a human sacrifice.
People are only as good as how they treat others. And if a God would choose to value unjustified belief over positive actions then that's not a God worth worshiping. It's a God worth pitying.