Actions really exist. They’re shaped by your intentions and they’re going to give results in line with those intentions. Those results can happen in this lifetime, but the possibilities of future lifetimes are shaped by our actions now.

"There were people in the time of the Buddha who said that actions didn’t exist at all. The only things that really existed were unchanging elements. Everything else was an illusion. The Buddha, though, said No. Actions really exist. They’re shaped by your intentions and they’re going to give results in line with those intentions. Those results can happen either in this lifetime or in future lifetimes, but the possibilities of future lifetimes are shaped by our actions now. Now, the Buddha didn’t say he could prove that to anybody ahead of time. At least he couldn’t give an empirical proof. But he did give pragmatic proofs.

One is that if you accept this teaching, you’re much more likely to behave in skillful ways. You can reflect on your behavior, and there’ll be a sense of well-being that goes with that reflection because you can see that you haven’t harmed anybody.

A second pragmatic proof is that it doesn’t make any sense to cut yourself off from possibilities. If you were to believe that your actions didn’t have any consequences, then you wouldn’t be able to accomplish anything with your actions. You’d just be waving your hands around in empty space. Whereas if you believe that your actions do have consequences and that it is possible through your actions to put an end to suffering, that opens possibilities that you would otherwise close off. Why close them off when you’re not one hundred percent sure?

So those are the pragmatic proofs. It’s up to us to decide whether they’re convincing and worth taking on as working hypotheses, because that’s what conviction is in the beginning: assuming working hypotheses. You say, “Well, let’s give it a try.” And the Buddha says that that attitude is perfectly fine. In fact, he even has a version of what’s known in the West as the Pascal’s wager. If there is such a thing as a future lifetime and it is determined by your actions, then you will be prepared for it. If there’s not, then at the very least you can hold yourself honorable in your behavior now, because the principles that the Buddha said give rise to happiness are harmless and noble."

~ Thanissaro Bhikkhu "Verified Confidence"