What did Sigmund Freud mean when he said........?

Freud said religion is a childish delusion and atheism is a grown up reality. So how do you interpret that? If you actually know what he meant by it, because you've read the book or studied Freud, then do you agree or disagree? Do you think Freud was right about almost everything or almost nothing. And if you say almost nothing, you have to have good reasons for thinking so....so lets hear em!