Om Swami
What is sin or wrong action, and how do I avoid doing it?
Sin begins with intentional harm
A fundamental way to see sin is hurting, harming or injuring anybody, at least intentionally, though that is perhaps a sin and not the whole answer. Right and wrong cannot be marked in black and white. When you experience quietude of the mind, you are unlikely to do wrong things or things you will regret later.
When we hurt somebody, when we are hurting, harming or injuring anybody in any way, at least intentionally, that is perhaps a sin.