This kind of guilt can come from the condemnation of the enemy of your soul. This is the kind of guilt that causes people to jump from bridges. This kind of guilt leads to hopelessness, despair and destruction. God's Holy Spirit convicts us in our conscience.
Many people refuse to listen to their conscience.
The more they reject it, the easier it is to ignore it until finally it doesn't bother them anymore. For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.