Can people who do not believe in God still attain true happiness ?

People who don't believe in God might attain fleeting moments of happiness on this earth, but they will feel continually lost, as though their whole purpose is missing, or struggle against a feeling of futility. It is very sad.

So many people have trouble with religion, and conflate God with religion, and that is an error. God is all around us, and within us. He is part of nature, and part of all living things. He goes so far beyond religion that man doesn't have the mental capacity to know Him.

But we can still have faith, and we can know that He exists.