Galatians 6:8 :
For he who sows to his own flesh will from the flesh reap corruption. But he who sows to the Spirit will from the Spirit reap eternal life.
So, here’s the problem. These people who are sinning are going to reap corruption. The simple fact is, there is a chance that some of them haven’t believed in Jesus yet. Paul has made this clear in the letter earlier when he said that he was in labor until Christ was formed in them.
The simple fact is that those who call themselves Christians, but live like the devil will end up getting what they deserve. Although we don’t know what is in a man’s heart, there is a good chance that they are not believers if they show no concern for what is right. It could be that they have only tasted God but have not yet committed to His program for their lives. That’s what a seed is. It’s a little program that grows. If they are planting a bad program, it’s a bad sign that they are on their way to reap Hell instead of Heaven.
Even though we don’t work for our salvation, God makes Christians hate sin and want to do what is right. When a supposed “Christian” is loving sin, God won’t be mocked. He knows when they don’t believe. We need to treat them with the seriousness that their actions deserve and help them before they die in this way.