Atheists, what are the most convincing theist arguments you heard of?

[Flavius]

I don't think I've ever heard a theist present a logical argument. The only thing you hear them say is how the hand of christ leapt down from heaven and they can now talk to God.

The worst thing theists say is "you need to believe first in order to see the evidence for God". That's called deluding oneself.

It's just plain circular logic. If your only proof for your belief is that you must believe in that belief, then something is wrong.

EDIT: Let's not forget about the placebo effect, if you convince yourself that Mr. God talked to you, then hell, it will become undeniable proof (to you).