I have a friend who is an atheist. She's an atheist because she sees no evidence to the contrary, though she has tried. I have another friend who's an atheist, but he has figured out the "where do we go when we die" thing: We live on forever, not as who we are but as the stuff we are made of, coming from the stars, going back into them, and so on. Recycling, as it were, rather than reincarnation. So I may not be me, but I won't be no longer existing, either, and I like that idea. When the more mystical ones seem a little too theoretical, I like the recycling idea.
I have a third friend who is not an atheist, but she's having trouble with being a theist because none of the definitions of God feel quite right. She wants to believe, but she doesn't know what to believe. I have suggested to her earlier that perhaps her deity is nature itself - as it is for many people. Just drinking in the world in all its mundane glory, rather than focusing on the unseen hand that made it.
You don't have to have a god to be spiritual. The experience of the spiritual side of things does not require religion.
But why do some of us believe in the big invisible hand, and some of us can't even imagine it? I read an article in some psychology magazine a number of years ago that suggested that faith may be genetic. Some of us seem hardwired for believing, and some of us aren't. A few biologists in recent years have explored religion from an evolutionary point of view: Why did humans evolve with what looks like a superstition? What good does it serve? I'll admit I haven't read their conclusions because I was put off by their supposition that faith is one of those wasteful things that has survived because it doesn't harm - like the appendix or homosexuality. Faith hasn't been a waste for me. Without it, I might be seeing a psychiatrist.
Yes, I am one of those theists. My atheist friends cannot understand why anyone believes in an unseen force that is labeled the boss of everything. I cannot understand how anyone can go through life without something bigger than themselves to be awed and inspired by. Prayer works for me. Feeling a connection to the divine works for me. I've tried to go without and I felt so lost it hurt. Atheism baffles me as much as theism baffles atheists.
These discussions are as helpful - and as fair - as arguing about vanilla vs. chocolate, football vs. baseball, Coke vs. Pepsi. We are drawn to certain things because of genetics, upbringing and personality. Because of our own personal likes and dislikes - and needs. It doesn't go deeper than that. No one has the whole truth about anything; we all see pieces of it, and we are all pieces of it. Each one an equally valuable piece. You can add a god to it or not; it's still about being human and connecting with other humans, doing your best, and being happy while you're at it.
Sometimes the discussion of atheist vs. theist is about where we go after we die. Or about morals and how you can't have any unless God smote you with His. I was raised by a theist and an atheist. They were married. They had the same values, were equally fond of and tolerant towards people, they were pacifists, and they both had a lot of humor about life, neither taking themselves seriously. Both loved me completely and wonderfully. The theist joked about haunting me after she died. Both she and her atheist husband did visit me after they died. Apparently, having a spirit doesn't depend on having a religion. Life is far bigger than that.
So I don't understand why someone doesn't believe in God, but that's because I personally cannot go without. It has never occurred to me that atheists must be lacking and/or are destined to go to hell. And contrary to what some atheists claim, all theists are not superstitious morons. The truth is, most people are good and most people try to do good, with or without a god. Love matters to all of us.
I think that is where atheists and theists can find common ground: Love and goodness are what matters. That is what makes humanity shine.
I understand her search; I didn't find a religious home until I found Science of Mind. I couldn't and can't relate to the Christian God.
Sometimes people become atheists as a reaction to the one not-so-nice God they were force-fed growing up. Unless they go exploring, they may never discover that each religion is a blind man trying to describe an elephant so pick your definition. The more fanatical theists need to realize this, too.