What does the phrase 'where two or three are gathered' mean in Matthew 18:20?

TL;DR:

Jesus assures us that He is present amid healthy confrontations against a sinning believer. These confrontations are a part of church discipline with the goal of loving restoration.

In Matthew 18:20, Jesus said: "For where two or three are gathered in my name, there am I among them." This verse falls at the end of a paragraph of verses on how to handle a personal offense with a believer that then escalates to discipline within the context of the church (Matthew 18:15–20). So, therefore, the appropriate context for "where two or three are gathered" is through the lens of church discipline and bringing a fellow believer trapped in sin back on track. Jesus affirms that He will be present in the midst of a healthy confrontation. The goal of confrontation about sin is to come to a place of repentance. Similarly, godly confrontation is not to be done from an attitude of pride or anger, but from gentleness and love. The end goal is not guilt but repentance and restoration.

from the old testament

In Old Testament law, accusation from one person wasn't enough to invoke any progress in a criminal case, but two or three witnesses made it valid (cf. Deuteronomy 19:15).

from the new testament

Jesus didn't come to condemn but to save (John 3:16–18). Jesus emphasizes that His first coming was to save rather than to condemn, reminding us that His presence among believers is aimed at restoring and redeeming. We, too, must approach others in conflict with love, hope, and a desire for restoration.
"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" (Matthew 18:18–20). Here, Jesus assures His disciples that when they unite in His name, their prayers and actions carry heavenly authority. Even in dealing with conflict, God is present among even the smallest gathering of believers.
Galatians 6:1–2 says: "Brothers, if anyone is caught in any transgression, you who are spiritual should restore him in a spirit of gentleness. Keep watch on yourself, lest you too be tempted. Bear one another's burdens, and so fulfill the law of Christ." Paul calls believers to gently restore those caught in sin while being mindful of their own vulnerabilities. The church is called to deal with conflict in a way that reflects the love and presence of Christ as described in Matthew 18:20.

implications for today

In context, this passage starts by saying: "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" (Matthew 18:15–17). These verses show the process for godly confrontation of a fellow believer who has sinned against you and is applicable to dealing with sin in the church in general. We are first called to go to the person who has offended us to seek restoration. When a personal, one-on-one approach has failed, we are called to bring one or two others in, and if that fails, we are called to bring them before the church. This way of handling conflict glorifies God and seeks understanding and restoration. In modern times, it's not common to address sin in fellow believers, because it's not socially acceptable to "judge" others. But, as believers, we are called to keep each other accountable for righteous living. Since none of us is exempt from being tempted and falling into sin, we must confront someone with the same care and grace we would like to be shown if roles were reversed. When we do take the plunge and do confrontation God's way, we can be confident that Christ will be with us—this is what Matthew 18:20 is all about.

understand

The phrase where two or three are gathered appears in the context of addressing conflict or sin in the church.
Where two or three are gathered to address conflict or sin in the church, God is there.
Where two or three are gathered there is opportunity to seek understanding and restoration.

reflect

How do you approach addressing sin or conflict with a fellow believer in a way that reflects Christ's love and presence?
How have you experienced Christ’s guidance or peace when participating in a difficult but godly confrontation?
How can you prepare your heart to address conflict with gentleness, humility, and a goal of restoration?

engage

How does the process outlined in Matthew 18:15–20 demonstrate both justice and grace in addressing sin?
Why is the presence of two or three witnesses important in both Old Testament and New Testament contexts, and how does it reveal God's wisdom in handling conflict?
How does understanding Christ’s presence in conflict resolution encourage us to handle such situations biblically rather than avoiding them?