Many Buddhist and nearly all Buddhist traditions accept the idea of rebirth, based on karma gained/lost throughout life. The differences between Buddhist traditions, in general, have to do more with specific details of rebirth, such as whether or not there is an intermediate state between births.
Secular Buddhist, as a tradition, interpret things differently, of course, suggesting that the Hungry Ghost (one of the Hell levels) realm is a state we might find ourselves in here and now. Some Zen Buddhists as well as suggest discussions of rebirth and different levels of Hells and Heavens are methodology rather than doctrine. Others would disagree, saying that “you must make the utmost effort to accomplish you enlightenment in this life, and not to postpone it into eternity, reincarnating throughout the three worlds” (Wumen Huikai, a famous Zen master).
What do I believe? For me, the traditional view isn’t really important. Buddhism allows me to decide what makes sense to me. My teacher has never said ‘If you don’t believe this, you are wrong’. Instead, the question is what is skillful, what is aligned with compassion?
Specifically, my teacher says “As a Buddhists, I’m not really thinking about what’s to come or what has already taken place. It is the now – the being right here right now – that is the underpinning on why I do this practice. If there is truth in that, then at the moment of transition (death) the same will be true. So what does it matter to figure it out now?” (Thich Minh Thien). He also suggests that when wondering about death from a ‘what happens next’ perspective, to take a look at the “Heart of Great Wisdom” sutra.
Which leaves it to me; what do I believe? Well, I don’t know. I’ve had a few ‘to strange to be coincidences’ events in my life. And a few feelings of reliving something that felt like a past life resurgence. But it is also true that I believe in the scientific method. And that the entire ‘if you are good you go to a good place…’ sounds like a fairy tale told to keep people in line. I am pretty skeptical about the ‘gain good merit by donating to our church/sangha/temple’.
The question really comes down to do I believe I have a soul; an everlasting “self” that goes from body to body, lifetime to lifetime. Where would I find this soul? It gets tricky here because a core Buddhist belief is there anatman or no-self. No permanent self or an unchanging, eternal soul. So what goes reborn? And anyway, where would I find that soul? It isn’t in my left arm, as if it gets chopped off, I’d still be me. The ego is a tricky thing and will do anything to protect itself, including creating the concept of a soul that continues on throughout all time.
So! To the question of ‘do I have a soul?’, I say – ‘I don’t know’. In other words, I have no proof one way of the other. This isn’t being an agnostic, it is simply being open-minded and realizing I don’t have all the information yet. Perhaps it is a bit more than that though because I don’t have all the info and I am ok with that.
So, if asked, I would say most Buddhist believe in rebirth, based on karma. But not all do, and that is ok, they don’t have to.
If asked what I believe, I’d say I don’t know, but my practice of compassion aligns with most of the worlds religions as being a good person, so maybe if one of those religions is correct I’ll be ok in the afterlife. If not, maybe I’ll be reborn a frog. But today, the focus should be today, being alive and living.