Not wanting to call one self an atheist anymore -- I can only assume you've gotten a lot of crap from 'Christians' and that that's the reason why. If so, I'm truly sorry.
Yesterday I prayed for an old man who doesn't/didn't believe in God either. Why would he, he have never experienced God, never felt like God have helped him in any way; he haven't seen any proof of God at all, and the Christians he have met have probably/typically been religious and unloving. I've heard that story before. Or maybe he have just gotten through life without ever meeting a Christian. Who knows. Anyway, I've been at his house several times since I do home visits with my computer company, and this guy uses profanity in almost every single sentence. A few of his sencentes are swearing only; after a while it almost gets fascinating.
He didn't have any money to pay me with, so I told him whattaheck, let me pray for you and bless you and we'll call it even. With a surprised look on his face he agreed. Turned out the God he did not believe in and did not believe existed still were able to let the guy feel something happen to his body, and after praying for his diabetes (not sure if anything happened there, we'll see on his next checkup), he wanted me to pray for his skin problems as well. 80 years as a non-believer, and after 1 minute he wanted me to pray for something else as well. Kinda funny.
Oh, and I don't blame anyone for not believing a word of it - it's still true. Pointless story? Well, no - the point is that the guy have gone through his entire life without ever meeting someone that could help him experience God ("how do you know it was God?" I know, I know. Nice coincidence though..
) but it took less than a minute for him to actually begin to question everything he believed/believes in.
Don't believe in God? Challenge a Christian to let you experience him. Get in their face, with an open heart. Words don't count, theories, "repent or you'll burn" - no, challenge them to let you experience God. The love of God is what leads to repentance, so ask them to experience the love of God. Is the Christian you meet unable to do so? Well, then I would question their Christianity. Go find someone else. Visit a church. How do you know which church to go to? The bible says that those who say they are in him (Christ) should live their lives like him. I.e. - if you do not find the love of Christ in their church, go elsewhere. Do you not feel like you're talking to a Jesus-like person? Go elsewhere. Even better, ask God to show you the people you should talk to. No one needs to know anyway, right? There's your chance to prove God wrong.