There are too many excuses that need to be made on God's behalf in order to explain the way the world works or is able to work for me to believe in Him (this is specifically the God of Christianity, mind you).
For instance, why did God used to appear and make miracles/life-altering mandates/moves in ancient times, and yet seem to stop completely when the human race started more consistently and accurately recording our history? I mean seriously... do you ever think anyone will ever again wield a wooden staff that can legitimately transform into a snake in front of an audience? And if not, why not? With God's help, Moses did it... supposedly.
Or look at the number of times God put the smack down on humanity or a group of people who pissed him off. Like Sodom and Gomorrah. God toasted those cities. Or the flood? And how much more should we be pissing him off today? What with gay marriages... legalized abortion... climbing divorce rates... and yet no sign of the wrath stick. Why is that? Because Jesus died for our sins? Be honest now... isn't that just another lousy excuse? Hell... I wouldn't be surprised if Jesus was invented/used as a way to explain why God no longer does those things... because somebody along the line realized that shit like that was never going to happen again. And why? Because they knew none of it was real to begin with.
Probably old hat to most of you, but it was new to me when I saw it a few days ago... a simple question with interesting ramifications for belief: "Why doesn't God heal amputees?". I mean... think about it... tons of people claim that the power of faith and prayer heal people's ailments from the common cold to cancer... and yet when it comes to something entirely visible and known to be permanent (like an amputated appendage) where is God with the healing? How fair is that? If it's a visible affliction, he doesn't heal it? WTF?
Again... simply too many excuses as to why God's action/inaction is so totally illogical. "The lord works in mysterious ways" is only going to get you so far before you start sounding like an idiot.