Good question. But it is a critical one.

There is nothing called good or bad.

Everything is relative. Certaing thing may addressed good for certain people while the same thing is addressed and bad for some other people. It is perspective.

But the religions have given standards. So, there by understanding levels have up risen to realize what is harmful and not.

And personally, I feel, if you are not harming anyone including yourself, it is good. Which means up to the standards...

The real conflict is between the standards. If people can live up to standards more than half of the problems will be solved on this planet.

Sadness is not everyone can understand this fact.