“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.There are four distinct phases to this process:
1) If your brother sins against you, go and tell him his fault, between you and him alone.
What Christ seems to be assuming is first, that an offense had actually occurred, and second, that the other person is completely in the wrong. In all of this one has to be aware of one's own sinful nature, take responsibility for whatever you did to contribute to the problem, and realize that in cases of disputes in the body of Christ it's rare that only one side is completely to blame for the ensuing mess.
In cases where one person has been sinned against by another person, it's clear how this is applied - you go to the other person and talk to them about it. By doing it just between the two of you, you're a lot more likely to have a receptive audience, avoid embarrassing the other person, or embarrassing yourself for jumping to a plausible, but unfounded conclusion. You also avoid the risk of offending the other person by accusing them of doing something they didn't do.
During this phase it's important to be open to the possibility the other person was doing the right thing and you didn't know something they did; that any offense you may've experienced was un-intentional; or they were not aware of the impact their actions had on you.
My post on "Combat Blogging" has some suggestions on how to approaching these kinds of issues.
What happens next?
If he listens to you, you have gained your brother.
This is the most ideal result - that things are worked out amicably and everyone goes away happy and reconciled, the air is cleared, and everyone can resume their normal business.
But this is not always the case - there will be times when the other person doesn't think they've done something wrong. Then we move to phase two:
2) 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.
The situation has become more serious - the offender has refused to listen to your complaint, or the dispute hasn't been resolved, so the next step in this parade is to involve other people. Christ doesn't specify who the other one or two people should be, but 1 Corinthians has something to say on the subject:
Or do you not know that the saints will judge the world? And if the world is to be judged by you, are you incompetent to try trivial cases? Do you not know that we are to judge angels? How much more, then, matters pertaining to this life! ... Can it be that there is no one among you wise enough to settle a dispute between the brothers...This suggests people who are wise and of good repute, who are able to help resolve if not outright settle disputes, aren't afraid to call a spade a spade, but won't let you get off the hook for your actions either. After all, if you've refused to listen to and accept your sibling's perfectly reasonable explanation for their action - then who'se the offender?
1 Corithians 6:2-3, 5
Unfortunately, there's always going to be cases where a sinner is sufficiently hard-hearted that even the counsel of two or three people will not move them. In such cases, we move to phase three...
3) If he refuses to listen to them, tell it to the church
By now the offender has refused to listen to the person they've offended, the counsel of the two or three other people you've brought in to help resolve the dispute, so now the church at large has to deal with the issue. If their collective counsel concludes that the offender is in the wrong, and the offender still refuses to repent of their sin, then the final phase of this process needs to be applied:
4) And if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector.
By now the offender's refused all counsel and correction that the church has had to offer, and in so doing remains committed to beliefs that excludes them from the body of Christ.
As such, the only course left for the Church is to acknowledge that and physically exclude them from the fellowship of believers of which they're no longer a part (hence the stricture "let him be to you as a Gentile and a tax collector").
Not only does excommunication publicly recognize the error of the impenitent's ways, it also separates them from other members of the body of Christ and possibly leading the weaker ones astray with their error.
This is another way to describe what's commonly called excommunication. It's an action taken by the body of Christ as a corporate entity after careful consideration, and is not something done by one person on their own recognizance. In fact, it's a responsibility assigned by God to the church as a whole, not to any single person or office-holder.
This leads to an interesting question - are Synodical or other church structures that allow a single person holding an office to exclude a member or church from the church body as opposed to the Church body as a whole - Scriptural?
How has this been done in the past?
As an example of how the early LCMS church dealt with an issue like this is described in the paper When is Enough Enough? by Daneil Preus. The paper discusse a number of cases, the best and most succinct dealt with the case of a pastor by the name of "Schieferdecker" who promoted a doctrine which the Synod deemed to be un-scriptural.
Over the course of things, the question of Pastor Schieferdecker's doctrine was closely investigated, his position clearly established by a council of faithful and wise men, he was given plenty of time to consider his position and his answers, and when he maintained his un-scriptural views, he was expelled from Synod by an act of the Church as expressed in it's convention. After he was expelled, he asked if Synod would consider reinstating him if he ever returned to the doctrinal position of the Synod. Synod assured him that such would be the case and indeed, eighteen years later, after he recognized and admitted his error, he was readmitted to the Synod in 1875.
All disputes are rooted in sin, and should be regarded as the expression of that sin. The objective in resolving our disputes should always to be reconciled - not necessarily to each other because two people agreeing to sin have still separated themselves from God - but to God who alone is perfect and holy. If both parties to a dispute humble themselves and are reconciled to Him, then they will be reconciled to each other, because God is not a God of confusion, but of peace.
All Scripture quotes from The Holy Bible : English standard version. 2001. Wheaton: Standard Bible