[485 words] If you, as a Christian, know for a fact that your brother or sister is living in sin, what are you to do? Depending on the sin, you might say. If it is a private matter, Matthew 18:15 and following give the prescription for the matter. If the brother or sister refuse to listen, there are potentially drastic steps to be taken. Galatians 6:1-2 tells us to go and bear up a brother who is in trespass. It tells us to do it gently or meekly. We are after his/her soul, not to just beat on him or… Log in or Register to save this content for later.