I was reading the admonitions in the Bible to avoid believers who are sexually immoral, or who regularly eat or drink to excess, practice idolatry or greed, are swindlers, foul mouthed, gossipers, or verbally abusive (1 Cor 5:11, Ephe 4:29). In this way we help them see that such behavior is sin. I’m very confused by this passage.
Paul was writing about those believers who persist in open sinfulness, making no effort to change. He’s telling us that these folks need to be shown that the public display of such behavior is unacceptable for a believer because it shows disrespect for the Lord and offers a poor witness to the world. He made it clear that he wasn’t referring to people who need the example of God’s love to draw near to Him, but to those who already call themselves believers and supposedly know what He’s done for them.
You understand that we aren’t encouraged to live holy lives to earn something, but to express our gratitude for having been given something. It’s our way of saying thanks. Those whose behavior reflects poorly on them are saying they don’t feel grateful for their salvation and are taking the Lord’s grace for granted.