God doesn't seem real to me. I have had experiences with gas stations and monkeys and feelings and velcro and rice. I don't know that I've had an experience that could only have been an experience with God.
When I tell believers that I don't believe that God exists because I don't see sufficient evidence, they often talk about how God must be known by faith. I don't know what this means.
I think they mean that faith is halfway between belief and knowledge, where belief is what one thinks, and knowledge is justified true belief. I think they mean that we have some information to nudge us toward belief that God is there, but not enough to know for sure.
They've confused invisible with ineffable. God can be known certainly, the Bible says, but he must be known by faith. It's not like God is a little kid playing hide-and-seek, and we're supposed to look for him, and we can't see him, but we can see his shoes peeking out underneath the curtains. Instead, the problem of faith is that God could be completely obvious yet still impossible to relate to on our terms.
Orthodox theologians, in the tradition of St Gregory Palamas, talk about God's essence and his energies. God's essence is what we can not know, it is internal to God, it is how the members of the Trinity are united. The energies are how God interacts with the cosmos, and how we could, conceptually, know God for sure. God is ineffable in his essence, but knowable in his energies.
To say that we can't know for sure that God exists makes God either a wimp or a bully.
If God is real and good and loves us, he ought to let us know that so we could all exhale. Does God not want us to know that he's real? God can't be unknowable and good. I suppose that God could be real and knowable and that some people still wouldn't believe in him because they don't want to. However, I get angry when a believer meets a non-believer and, from the fact of their non-belief alone, assume they are either uninformed or dishonest. This understanding of God can't allow for honest doubters.
Some people say that God is real and good and loves us and he's not a bully, he's actually quite nice, so nice, in fact, that he keeps himself hidden from us so that we can be free to believe in him or not. This is on a par with believing that God can make a rock so heavy he can't lift it, or, in the formula preferred by Mr Andrews, this is as if God could make a burrito so hot it could burn the roof of his incorruptible mouth. This God could only be nice if knowing him were irrelevant.
One of the problems that I have in knowing if God is real is that I know how much I want God to be real. I want to know that I can live forever in heaven and that God will bring perfect peace to the world and that God loves me and gives me a name. I want to be free from worrying about my reputation and my success and my possessions and my self. The claims of hope that Christianity makes are so good it seems more likely to me that I would believe them because I want them to be true than because they're real. I compulsively second-guess myself. Maybe Lexapro will help with that, but I don't think it will. I think that if God's real, God, and only God, could make me rest in belief in him.