"I don’t feel guilty."

People often don’t feel guilty when they sin because they have "seared" their conscience. They have removed the batteries from the smoke detector of their conscience, so that they can sin without interruption. The way to resurrect a deadened conscience is to go through each of the Ten Commandments, reminding the person that they know that it’s wrong to lie, steal, commit adultery, etc. Always preach the Law along with future punishment, then pray that the Holy Spirit will come upon them and cause them to be convicted of sin, righteousness, and judgment to come.