Responding to Sin in the Church, Part 1

By Robb Brunansky

Published July 23, 2026

The Apostle Paul in 1 Corinthians 5 raises the critical question, “How should we deal with sin in the church?” Sometimes this query is discussed under the topic of church discipline. What does it mean, and when should a church discipline a member who is living a life of unrepentant sin?

Many times when we think about this topic, we immediately jump to the classic statements from our Lord Jesus Christ in Matthew 18 about the four-step process of church discipline. While this passage is foundational, assuming these verses are the only place the New Testament addresses this topic could cause Christians to miss some important biblical context for the purpose and process of church discipline. The Bible has much to say about church discipline, and to understand the biblical teaching on this practice requires keeping it in the overall context of Scripture.

Church discipline has its roots in the Old Testament. When we think about preserving the purity and holiness of the church, we must go back to God’s purposes for His people. The Lord begins to unfold His purposes in redemption when He reveals why He has selected Abraham to be the father of Israel (Genesis 18:19). Abraham was chosen by the Lord so he and his offspring might be holy. Additionally, God redeemed Israel from slavery in Egypt so they might be a holy nation (Exodus 19:5-6).

That theme of holiness continues as God gives the law to the Israelites through His servant Moses (Leviticus 19:2). This principle is woven throughout the entire Old Testament such that God’s people were called and required to be obedient to His Word and holy, separate from all the wicked and rebellious nations.

When God’s people failed to live up to this standard of holiness, those who violated the covenant were cut off from their people and / or put to death. We see repeatedly in the Law that certain people were to be cut off from the people, or even put to death, for their sins to preserve the purity of the nation of Israel. There were horrific consequences for violations of this holy standard after the golden calf incident (Exodus 32) and Achan’s treachery (Joshua 7).

God’s zeal for His people’s holiness is no less now than it was in the Old Testament. The Lord is still greatly concerned that His new covenant people, the church of Jesus Christ, remain holy and preserve His holiness. In the New Testament, Peter picked up on the holiness language from Exodus, reminding Christians that we are called to be what Israel under the law failed to be – a nation of people who belong to God (1 Peter 2:9-10). Paul also reminds the New Covenant church that it is called to be a holy people who manifest the character of the God who has saved us (Ephesians 5:1-2).

This continuity of the Lord’s holy standard is why we find instructions about, what we commonly refer to as, church discipline, scattered throughout the New Testament. The process in Matthew 18 is actually based on the aforementioned Old Testament call to preserve the holiness of God’s covenant people. Jesus’ statements here didn’t drop out of nowhere, but rather came as a reminder that God wants us to purge the church of those who live in persistent, unrepentant sin. The church cannot have among its members people who participate in the life of the body but who live like unbelievers.

Paul also speaks about what to do with those in the church who are rebellious against God (Romans 16:17-18). He warns these believers to watch out for those who guard their own interests, flatter others, and seek to twist Scripture for their own ends. If such people have an influence in the church, they will corrupt the purity of the bride of Christ. In another passage, Paul warns that Christians cannot allow people, who live in flagrant rebellion against God and seek to divide His people, to have a place in the church (Titus 3:10-11). Discipline must be part of the life of the church if the people of God are to be what they are called to be: holy!

The first example we have of church discipline in the New Covenant Church mirrors in many respects the case of Achan, with Ananias and Sapphira (Acts 5). God personally made an example of these two for the entire church to learn the importance of holiness among His people – and the lesson was for sure received by the body!

Most of the time, church discipline is not as shocking as it was in the book of Acts, but God’s zeal for holiness among His people is no less intense. The process for church discipline is not to cut someone off from God’s people through physical execution, but to remove them from the church.

One of the great challenges we face in administering church discipline, even with the principles laid down for us in the New Testament, is that we don’t have many case studies where we can watch how the early church applied those principles to real life situations. However, in 1 Corinthians 5, we have just a case study of church discipline, and we can see how to deal with sin in the local congregation. Throughout this chapter, Paul will show us how we might apply what Jesus and the apostles taught in the New Testament about church discipline and unrepentant sin amid the body of believers. We will begin to unpack those principles in the next post.