I cannot believe in God when there is no scientific evidence for the existence of a supreme being and creator.

God is necessary, and therefore must exist... But I know that he does not and cannot exist... Don't you understand that a man with these two thoughts cannot go on living?

That God does not exist, I cannot deny, That my whole being cries out for God I cannot forget.

A great many people say we have language and imagination to posit creators, interveners, and agencies that we can't actually prove. And yet some people experience God within them--these experiences are not drawn-up hypotheses. It's possible those of us who don't feel God within them have deficient brains that aren't capable of such experiences; or alternatively, the people who experience these things have brains that somehow create them. As near as I can tell, the jury is out on that. I may be a non-theist who doesn't include a god concept in my religious orientation because I have an incompetent brain, or perhaps theists have brains giving them inaccurate information.

God exists...but only in our minds

The existence of God cannot be used as any scientific hypothesis: it is something different that transcends science. [...] I would be a terrible theologian if I tried to do an experiment to prove the existence of God, and a terrible scientist if I tried to explain my experimental data by hypothesizing the existence of God. [...] I'm always annoyed when people ask me about my religious opinions in interviews. I don't think they ever ask that of footballers, singers, models, categories for which I have the utmost respect. Interviewers implicitly assume that scientists possess privileged knowledge of God, but this is not true.

A necessity of my reason constrains me to believe the existence of God, because I can in no other way account for my own existence.… I know that I am. I am either uncaused, or self-caused, or caused by a cause.

Why don’t you believe in God? I get that question all the time. I always try to give a sensitive, reasoned answer. This is usually awkward, time consuming and pointless. People who believe in God don’t need proof of his existence, and they certainly don’t want evidence to the contrary. They are happy with their belief. They even say things like “it’s true to me” and “it’s faith.” I still give my logical answer because I feel that not being honest would be patronizing and impolite. It is ironic therefore that “I don’t believe in God because there is absolutely no scientific evidence for his existence and from what I’ve heard the very definition is a logical impossibility in this known universe” comes across as both patronizing and impolite.

I'm an atheist: I don't know what it means to believe in God.

Something may happen to a person, and will make that person believe in the existence of God while some will happen and the person will think there is no God.

I am assuming that God exists and I am glad that there is no way to prove this. [Because] I would run through the proof once, and then I'd forget it, and I would never speculate about spiritual things and mysteries otherwise. And, I think, my life would be very incomplete.

"So you truly do not believe in God?"
"I find no reason to, in nature... If the idea of God is unknown in the state of nature, it must then be a human invention."

The human mind may know God, and learn of God, though it has no terms by which to explain Him; it may think of Him as Absolute, as Infinite, as Personal, while it may never in this life be able to fathom the full meaning of these sublime ideas.

My mind is incapable of conceiving such a thing as a soul. I may be in error, and man may have a soul; but I simply do not believe it. What a soul may be is beyond my understanding.