[Protagoras]

If there is no God and therefore no reward or punishment because there is no afterlife, how can there be such a thing as right and wrong?

I would submit that in that case, there are only actions and consequences in the present life.

[TheOtherOne]

If there is no God and therefore no reward or punishment because there is no afterlife, how can there be such a thing as right and wrong?

It is sad that some people are only good to get their reward and avoid punishment.

[Stone Mountain]

If there is no God and therefore no reward or punishment because there is no afterlife, how can there be such a thing as right and wrong?

So the only reason theists act morally in this lifetime is because they are performing a cost-benefit analysis?

[orionblamblam]

> If there is no God and therefore no reward or punishment because there is no afterlife, how can there be such a thing as right and wrong?

Because right and wrong do not need to be related to a fear of punishment, in this life or any other. In simplest and simplistic terms, "right" morally is that which provides the best chance for your genes to propogate. Thus murder is out, because people will come kill you for it; rape is out for the same reason. I've yet to come across a bit of (generally accepted) morality that can't be defined in this way.

[exnavychick]

If there is no God and therefore no reward or punishment because there is no afterlife, how can there be such a thing as right and wrong?

Don't you ever do (or not do) something, just because it "feels wrong", or because it's just innately abhorrent to you? Don't you ever do something nice for someone without thinking about in the context of your faith or what you might get out of it? (Either spiritually or materially or even egotistically?)

Some things are just so obviously right or wrong that you don't need religion to know it, imo.