The following is an excerpt from The MacArthur New Testament Commentary on John 20.

If you forgive the sins of any, their sins have been forgiven them; if you retain the sins of any, they have been retained.” (20:19–23)

As part of their witness to Him, the disciples would have His authority delegated to them. “If you forgive the sins of any, their sins have been forgiven them,” Jesus told them, but “if you retain the sins of any, they have been retained.” This verse has been misinterpreted by Roman Catholics to mean that the Roman Catholic Church has had the apostles’ authority to forgive sins passed down to it. But Scripture teaches that God alone can forgive sins (Mark 2:7; cf. Dan. 9:9). Nor does the New Testament record any instances of the apostles (or anyone else) absolving people of their sins. Further, this promise was not made to the apostles alone, since others were also present (Luke 24:33). What Christ was actually saying is that any Christian can declare that those who genuinely repent and believe the gospel will have their sins forgiven by God. On the other hand, they can warn that those who reject Jesus Christ will die in their sins (8:24; Heb. 10:26–27).

This was not new information to the disciples, since the Lord had spoken very similar words long before in Caesarea Philippi: “I will give you the keys of the kingdom of heaven; and whatever you bind on earth shall have been bound in heaven, and whatever you loose on earth shall have been loosed in heaven” (Matt. 16:19).

Here Jesus spoke of the delegated authority of believers. He told Peter, the Twelve, and by extension all believers, that they had the authority to declare who is bound in sin and who is loosed from sin. He said believers have the “keys of the kingdom,” the realm of salvation, because they have the gospel truth that saves (Rom. 1:16; 1 Cor. 1:18–25). Christians can declare that a sinner is forgiven or unforgiven based on how that sinner responds to the gospel of salvation.

The church’s authority to tell someone that he is forgiven or that he is still in sin comes directly from the Word of God. In Matthew 18:15–20, the Lord taught His disciples (and by extension all believers) that if a professing believer refuses to turn from his or her sin, even after being privately confronted (vv. 15–16) and publicly rebuked (v. 17), then the church is commanded to treat that individual as an unbeliever. Those within the church have both the authority and the obligation to call the sinning brother back to repentance (vv. 18–20), and to let him know that because of his blatant disregard for the Word of God, he has subsequently forfeited fellowship with the people of God. The reality is that he may not be a child of God at all (John 8:42; 14:15; 2 Cor. 13:5; 1 John 2:3–6).

Believers have the authority to do this because God has given them His Word as the supreme standard by which to judge. Their authority does not come from anything within them; it is not founded on their own personal righteousness, spiritual giftedness, or ecclesiastical position. Instead it comes from the authoritative Word of God.

That which the Scriptures affirm, Christians can dogmatically and unhesitatingly affirm; that which the Scriptures denounce, Christians can authoritatively and unapologetically denounce. Believers do not decide what is right or wrong, but they are to declare with boldness that which God has clearly revealed in His Word. Because the Scriptures present sin as an affront to God, His people must be faithful to confront it. Insofar as their judgment corresponds to the Scriptures, they can be certain that it harmonizes with God’s judgment in heaven.

When people reject the saving message of the gospel, denying the person and work of Jesus Christ, the church has divine authority, based on the revealed Word of God, to tell them that they will perish in hell unless they repent (Luke 13:1–5; cf. John 3:18; 1 Cor. 16:22). Conversely, when people profess faith in Christ as their Savior and Lord, the church can affirm that profession, if it is genuine, with equal confidence—based on passages like Romans 10:9, “If you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you will be saved.”

The church’s authority comes from the Scriptures. Because Christ is the head of the church (Eph. 1:22; 5:23), the Word of Christ (Col. 3:16) is the supreme authority within the church. When believers act and speak in accord with His Word, they can do so knowing that He stands in agreement with them.