Laughter is the very essence of religion. Seriousness is never religious, cannot be religious. Seriousness is of the ego, part of the very disease. Laughter is egolessness.
Yes, there is a difference between when you laugh and when a religious man laughs. The difference is that you laugh always about others — the religious man laughs at himself, or at the whole ridiculousness of man’s being.
Religion cannot be anything other than a celebration of life. And the serious person becomes handicapped: he creates barriers. He cannot dance, he cannot sing, he cannot celebrate. The very dimension of celebration disappears from his life. He becomes desert-like. And if you are a desert, you can go on thinking and pretending that you are religious but you are not.
You may be a sectarian, but not religious. You can be a Christian, a Hindu, a Buddhist, a Jain, a Mohammedan, but you cannot be religious. You believe in something, but you don’t know anything. You believe in theories. A man too much burdened by theories becomes serious. A man who is unburdened, has no burden of theories over his being, starts laughing.
The whole play of existence is so beautiful that laughter can be the only response to it.
Only laughter can be the real prayer, gratitude.
-Osho, "A Sudden Clash of Thunder, #9"