SIN is what we do and think. The definition of Sin varies from religion to religion; from belief to belief, but GUILT depends on the person and the “time” during which he “FEELS” guilty.
So essentially, SIN is based on what one DID or THOUGHT (Jesus says: if a man lusts after a woman, he has committed adultery in his heart) but GUILT is what a person “feels” or “is made to feel about what he did or thought”. Herein lies the difference.
Ashoka the Great killed millions in the war of Kalinga but did not feel Guilty, but somewhere thereafter he FEELS GUILTY, so he was CONVICTED OF HIS GUILT and gave up war.
David overcomes his guilt after committing adultery with Bathsheba till Nathan CONVICTS David of his guilt.
Guilt is a personal conviction, whereas SIN is an ACT..
The best part is that one could SIN and never FEEL GUILTY.
And if we are LUCKY, God will not bring up a person to show us our SINS and make us FEEL GUILTY!!