Agnostics don't have to worry about what they say. Atheists do because they often have some beef with god. I'd prefer that their were some benevolent creator of the universe and a place to go when we die. All that makes life so much more magical, but I can't quite seem to get excited about religion, especially all the needy asking god for things. I tried bible study for a while. Group prayer kind of pisses me off. It's all "Seriously people, I wasn't going to cure your mother's heart when just you were asking, I don't care how many people you get to join you. I'm not bailing out everyone who overindulges in bacon."
Also, the concept that god is this huge egomaniacal entity that really needs people to congregate and sing about how great he is, that also irritates me.
Worst is the idea that god will repay you ten times what you send to certain evangelists. If they packaged and sold all of those bad debts we'd have a serious economic crisis.
Too many people look at god as a chump who will give them things or some hugely vain entity that must be appeased with vast volumes of praise. On the other side is the one where he's vengeful and vindictive, casting people into the eternal flames because they didn't trust some corrupt religious official. None of these portrayals is the least bit flattering.
Then you've got Jesus who was all about love and forgiveness. I can get behind that kind of god, but I can't really see a point in all the worship, foofah, and hoodininny that goes along with the religion. So I try to make the world a better place by my actions and trust that if there is a god that he is neither a chump nor a jerk. Basically, I can't see me acting any differently with religion than I do now.
It certainly doesn't help that according to George W Bush, we should be bombing a lot of churches, as many are full of people who hate our freedoms and want to take them away.