What does the Bible say about company with sinners?

In 1 Corinthians 5, Paul advises the church not to keep company with those who claim to be brothers yet live in unrepentant sin, such as fornication or idolatry. This doesn't mean believers should isolate themselves from all sinners, as they would have to leave the world entirely, but rather that they should not associate closely or have fellowship with those who openly defy God’s commandments. Paul's concern is that such behavior undermines the holiness and witness of the church, as followers of Christ are called to live distinctly from the world in light of their redemption.