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

[Nonpareil]

Incidentally, while I agree with Whateverist and other posters here in saying that I have never come across any arguments for the existence of gods that struck me as at all compelling, there was one bit of theistic logic that I did actually find quite interesting.

There is a series of science fiction novels by an author named Dan Simmons - The Hyperion Cantos. Think of it as The Canterbury Tales, but in space; a group of pilgrims are making a trip to a place called the "Time Tombs" to petition a godlike entity to grant various wishes of theirs, and each takes it in turn to tell the story of where they came from and what they are wishing for along the way.

One of these pilgrims is a Jew whose daughter has been "cursed", or inflicted with a disease, or something of that sort, which is causing her to age backwards. She's already been reduced to infancy, and he hopes that the entity they are traveling to see will be able to cure her of her condition before she dies. Along the way, he continually questions his own faith, focusing around the question he sees as being the heart of the Binding of Isaac: How could a loving father bring himself to kill his own child, and how could a good and just god ask a man to do this for them?

The ultimate conclusion that he reaches actually struck me as a very interesting little take on the story. The answer, he reasons, is in the very nature of the test. As most versions of the story tell it, God was testing Abraham.

As he figures it, Abraham was testing God.

Of course, it's not an argument in favor of God's existence or anything, but it struck me as a very neat and intelligent little take on the story anyway.