Because other people matter and building a caring and just society means we’ll all get further in the one life we have. If you require the threat of eternal punishment to do the right thing and be a good person I’d question if you truly are.

Of course not everyone can or will do the right thing without being threatened with punishment... but I think it's possible to make the world a better place in general if we can at least tone down the amount of bad things happening, even if it requires "threatening" the people that need it to behave.

Otherwise I think laws wouldn't exist.

But if there is no afterlife, why does building caring and just society matter? If you (and everyone else, and the universe) is going to die, you might as well train your conscious and trample on the lives of others if it leads to success in life.

> But if there is no afterlife, why does building caring and just society matter?

Because some (most?) of us are empathetic and compassionate people. We care about others and hurt when they hurt. We want to live in a just society and want to leave behind a just society for others after us.

The fact that it requires „training your conscience“ to „trample on the lives of others“ suggests that such an outlook is not a default state of being.

Most of us are egoistic a-holes, and most of us like to build false picture of them in their minds so we can have nice time thinking that we are good persons.

Faith, ethics, etc., are survival mechanics of a higher-level organism relative to individual human. These matters will by definition not make sense if you view them only from the perspective of a standalone individual—and it is fine, because humans really do not exist as standalone individuals.

Even without believing in a life after this one, a lot of people seem to find immense value in living ethically/morally for its benefits in this life: a clear conscience, building trust, strengthening relationships, etc.

Even though life can be cruel, there seems to be an overarching goodness built into the universe that benefits those who float in its current.

Some people don't need a deity to treat others the way they would like to be treated.

> Why would it matter if there is no life after this one? If there is no life after this one, maybe you should just "get over it".

Because for as long as we are capable of caring, we should care that other people have to live with the consequences of our actions.

> we should care...

But that's my question: if there is no afterlife, why?

Are you asking really to ask, or is this a entrance into a philosophical debate?

The answers so far are a little snark, however this topic has been debated for a long time and most of the pro/cons can be listed rather easily.

for one, it is just rhetorical, nobody knows if there is really no afterlife. Every bad you did might be a Jira ticket in hell now.

Do you care about people _now_, even though their existence is finite and at some point anything you may or may not have done to affect them will cease mattering?