That varies from individual to individual, but most of us believe in reincarnation* of one kind or another. Most of us think that after you die, you review the things you did in this life, decide what you want to learn next, and come back again as a human baby to learn it.
Some of us also think that there is a period of time when you can rest between lives. We tend to refer to this as "The Summerland." That's the place you meet up with loved ones and so on.
We don't have anyplace where you are punished, like the Christian concept of Hell, because what would be the point? If you messed up, and didn't learn anything at all in your whole life, then the obvious thing to do is come back and try again!
Part of this question really hinges on the question "What are we here for?" As I have always said, we are here "To have fun, learn stuff, and help other people have fun and learn stuff." Most of us, I think, would agree. No room there for vengeance or punishment.
*Quite a few of us can remember previous (or future) lives, and some can even remember the stuff that happens between lives. When you have memories, as clear as your memories of your childhood here, of being other people in other times, I'm not sure that the term "believe in" applies. "Believe in" implies that you don't know, but you have chosen to believe something anyway; to take it on faith. When you have memories, you may as well say you "believe in" the outdoors when you are inside sitting at your computer. You may not have seen it in a while, but you know perfectly well it's actually there!
A lot of stuff in our religion is like that for a lot of us. We don't need faith; we have experience! But the language doesn't lend itself easily to that, so we "believe in" reincarnation. Back to text.
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