If one has the authority to recognize who is God’s representative, they also have the authority to recognize who is not. You will know them by their bad fruit (Matt. 7:19-20). You will know them by their sin.
In Matt. 18:15-20, Jesus instructs his disciples on what to do when they come across a brother who will not repent.
“If your brother sins against you, go and tell him his fault, between you and him alone. If he listens to you, you have gained your brother. But if he does not listen, take one or two others along with you, that every charge may be established by the evidence of two or three witnesses. If he refuses to listen to them, tell it to the church. And if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector. Truly, I say to you, whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven. Again I say to you, if two of you agree on earth about anything they ask, it will be done for them by my Father in heaven. For where two or three are gathered in my name, there am I among them.”
Jesus is simply instructing the disciples to confront their brother who is committing sin, and bring the truth to this brother: God’s representatives shall not sin. If he listens, and accepts that truth, his union with Christ is confirmed. If the sinning brother does not listen, Jesus advises to bring more believers to confront him. This allows the God’s truth to be affirmed by others, and it protects the accused from false accusations. If the sinning brother does not listen, Jesus commands the whole church to affirm God’s truth in unity. If the sinning brother still does not listen, Jesus says this man cannot be recognized as having any union with Christ, as he bears no good fruit.
While this may just seem like a wise strategy, there is also a clear point when the disciples are authorized to say this brother is an unbeliever. It is not until the church has addressed the matter. The words in verse 17 make it clear, only after he does not listen to the whole church, is he to be considered an unbeliever.
Why is it that the church has the authority to decide who is or isn’t a believer?
Because the authority that Jesus gave to Peter, he also gives to the church. Notice verse 18:
Truly, I say to you, whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.
Jesus uses the same “binding/loosing” metaphor he used in Matt. 16:19, when Jesus was giving the keys of the kingdom to Peter. In that context, what Peter was confessing on earth, so it was affirmed by God in heaven, for God gave Peter the ability to make the confession.
In Matt. 18, what the church is declaring about the sinning brother here on earth, so it shall be affirmed by God in heaven, for God is giving the church the ability to recognize bad fruit. In other words, they are, by God’s grace, recognizing what is already true in heaven.
With that in mind, it’s no wonder that Paul condemns the Corinthian church for not removing a sexually immoral man from the church (1 Cor. 5:1-5). Paul even expects them to do this as an assembly (v.4). After all, this is a letter to the whole church, not just to the elders.
What about the churches ability to recognize good fruit?
As the ministry of the word goes out into the world, God will bring more into the fold, and naturally the church has the authority to affirm their membership into God’s kingdom. Consider the Great Commission in Matt. 18:18-20. Few disagree that the ministry of evangelism and disciple-making is a call upon all Christians and therefore, a call on the local church. While this passage says nothing of church membership, it stands to reason that if churches are making disciples, they have to decide who they are discipling. Jesus again brings up the issue of authority:
And Jesus came and said to them, “All authority in heaven and on earth has been given to me. Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age.”
This isn’t just a commission. God deputizes the church to make disciples with the same authority Jesus possesses. To put it all together, the local church is given the authority to preach the gospel, recognize who is responding to the gospel by their good fruit, and raise them up as disciples. Elders equip the church for this ministry, but the church was given the authority to carry it out.
Next, we will see why the authority of the church extends over elders.