1 Corinthians 5:13 (ESV)

13 God judges those outside. “Purge the evil person from among you.”

The command to purge the evil from your midst is taken directly from Deuteronomy (Deuteronomy 17:7; Deuteronomy 19:19; Deuteronomy 21:21; Deuteronomy 22:21, Deuteronomy 22:24; Deuteronomy 24:7). In the Old Testament, the kingdom of God was represented by the nation of Israel. God commanded the Israelites to shut out from the kingdom those who violated his covenant.

Today the church represents God’s kingdom on earth. God has given the keys of the kingdom to the church (Matthew 16:18–19), and one of its responsibilities is to shut out evildoers. To be outside of the true church of God is to be outside of the kingdom (Matthew 16:18–19) and to fall under God’s judgment.