How do you know God exists?

I said in my last post that I wanted to learn to love God, but actually, I just want to know him first. I said that I think I stopped believing in God at one point in my life, but honestly, I don't know if I ever really believed to begin with. Growing up, God was always a given. The questions were always about where to find God, what kinds of things God could do, what would God want you to do. But no one ever addressed the issue of whether he existed to begin with.

I know the story of "doubting Thomas," who refused to believe that Jesus had come back to life without proof. I also know that the point of the story was to not be like Thomas. Thomas' faith was weak. He had to see to believe. But I just can't help it. I'm a Thomas. I would love to believe that there is an all-powerful being that only wants what is best for me and who will always look over me. Of course, I'd also like to believe that a jolly elf brings gifts to people who have been good all year on Christmas eve. I want all the things that God can do for me. It's just the believing that he exists to begin with that I have the trouble with.

I thought a good place to start would be by researching. I found a great blog called Conversion Diary by a woman who was once an atheist and has since converted to Catholicism. I went back to her very first blog post hoping to see what kind of proof she relied on. Unfortunately, it seems like even then she was ahead of me. Starting her blog, she had already gotten to the point where she could say that she believed in a creator. Of course, she also states that she had been studying the topic for two years, so she did have quite a head start on me.
A few days ago, I had dinner with a friend who had not been born into a religious family like I was but who had "found God" several years ago. I asked her how she knew there was a God, and she answered simply that she had asked God to prove himself to her (ahah! I'm not the only doubting Thomas!). It wasn't the answer I had wanted to hear. I was hoping she'd found some empirical evidence or something. A book or argument that made sense to her. I wanted something concrete that I could grasp.

I was also scared of that answer because in my research I'd come across a book written by atheists who had converted to Catholicism. In reading the reviews of the book, I discovered that many of the authors had experienced dramatic events shortly before their conversions. I don't know exactly what a conversion experience is, but I do know there are two things I don't want. I don't want anything bad to happen, and I don't want any apparitions, especially of the ghostly or scary kind (yes, I admit that while I have trouble believing in God, I have no trouble being scared of ghosts). In fact, I'd rather just avoid any kind of drama all together if I can help it. Luckily, my friend assures me that God tailors it to each individual and his or her needs.

Since then, I've been thinking about asking God for some proof, but I'm still not quite sure I want to do it yet. There are still a few things holding me back that I want to deal with first. But I've certainly been thinking about it a lot.