Every society has defined certain rules, if one cross those rules, the person is found guilty, as he or she has performed a sin. Right and wrong are a social phenomenon, a different set of rules in every society. But when we are spiritually aware and conscious we are more inclined towards the human growth. Being spiritually aware means you are aware of your deeds.
To elaborate a little more, when we feel that we would not like to do a certain thing to do, to our self, we would also not do it to others. If some action does not work for us we would not want to do it to another person.
I remember this quote from my school days, it was written in Hindi:
वैसा ही व्यवहार करो जैसा तुम अपने लिए चाहते हो (waisa hee vyavahar karo jaisa tum apne liye chahte ho) Translation : Behave as you would like for yourself.
Inculcating the guilt, fear, and shame keeps a human away from spiritual awareness, spiritual evolution, and growth as a human.
Spiritual consciousness is the key, to stay away from guilt.