One is what I call moral guilt or ethical guilt and the other is what I call emotional guilt. Emotional guilt is the feeling of being guilty. It's possible to feel guilty when we're not guilty, and it's possible to not feel guilty when we are. The other guilt that I'm talking about, other than the feeling, is the true moral guilt. In other words, there is a condition of true moral guilt in which a person is culpable, worthy of blame, morally responsible for something he did.
Some people feel bad in their heart about something they did that was truly wrong.
In that case you have true moral guilt and also emotional guilt. Other people do something that is truly wrong and feel no emotional guilt whatsoever. We generally call those people sociopaths. So there are two categories of guilt. Both are very important in our discussion and I think the emotional guilt is an existential experience that God gives us when we break His law.