I don’t know why one would do the right thing if it appears that they are only punished for doing so. I disagree with the premise of the question. I don’t think that people are punished/rewarded for doing the “right” or “wrong” thing nor do I believe that good ought to be rewarded nor evil punished nor vice versa.
I don’t know if the “right thing” exists. I certainly feel like it does but I don’t want to choose any moral framework that might call a thing right because an equally valid framework would call that same thing wrong. This is why I also can’t subscribe to the belief that there exists any sort of ought–not that good/evil or right/wrong ought to be rewarded/punished but also that there is no ought in terms of action.
I don’t view anyone as being punished for doing the right thing either. Job wasn’t punished, and definitely not for doing the right thing. Job did the right thing and there were also bad things that were done to Job. The same happens with all of us: that we do right things and wrong things and that both good and bad things happen to us irrespective of our morality. They are not punishments or rewards but just things that happen. If Job were to have viewed his circumstance as a matter of happenstance rather than as divine judgment his circumstance would not have changed. Rather, what would have changed would be his cognition regarding his experience. For Job, as a man living in a time where the existence and morality of G-d was thought to be absolute, his questions of divine justice were eventually answered and he was given reason to act righteously for its own sake. I disagree with this conclusion, however, because anything under that framework cannot be for its own sake but ultimately has the purpose of serving G-d. As someone unsure of his own faith the wisdom given in this text is not sufficient for me. I need to start from scratch.
I can at least tell when a good thing or a bad thing happens to me–at least based on how it feels to receive it immediately and over time–but I can’t always tell when I am doing a right or a wrong thing. Despite my inner moral center I can’t always map that right is followed by reward and wrong by punishment or vice versa or any correlation at all. And yet I still feel immensely compelled to do the right thing.
The only way I can be punished for doing the right thing is if that device that pulls at my heart to act in a certain way feels guilty or incorrect or awful or slightly awkward or uneasy about what I did. But then in that case I would feel as though I did the wrong thing. I may be punished in the broader sense: say I give my cash to a homeless father and his daughter and then cannot buy my own dinner for the night. However, that still feels more like a sacrifice than a punishment. Even if there were a hypothetical scenario where I was punished horribly every time I did the “right thing” it would still feel wrong to act against my moral center. If, however, this supposed punishment were to transform my previously “right” action into a “wrong” one then the punishment wouldn’t be for acting “right” but rather just a reason to act “right” by making the choice that was previously “wrong” but is no longer. In other words, I do the “right thing” because I feel that it is right–not because I weigh the pain of immorality as worse than that of ephemeral physical or mental anguish but–because if morality is not for its own sake than it is grounded in immorality and cannot stand. I do the right thing so that the right thing exists.