Matthew 18 is a series of portraits of grace: the grace to those who humble themselves as children, the parable of the lost sheep, and the parable of the unforgiving servant, with its attendant call to forgive our brothers 70×7 times. It also includes a warning against putting a stumbling block in front of other people (which is not at all the same as the modern notions regarding “being offensive”; rather, it is about not being the occasion of tempting others to sin).
In the midst of this is a short passage that, if considered carefully, provides discomfort for various Christians. I am referring in particular to vv 15–20, which in some Bibles comes under the heading “If Your Brother Sins Against You.”
The little passage is uncomfortable for those who pretend the Church has no authority, who think “Judge not, lest you be judged” means accepting everyone no matter what they do. In these verses, Jesus gives the Church the authority of binding and loosing, so that the impenitent are set outside the Church, with the promise that such activity will be ratified in heaven. All of that implies, of course, that the Church is supposed to exercise discipline. It implies that there is such a thing as sin, and more importantly, that recalcitrance (an insistence upon maintaining wrongdoing; a refusal to be corrected) is grounds for expulsion.
But the details of the passage also prove problematic for those who like to think of these verses as outlining “the steps of discipline,” which in fact is simply not true.
These verses do not center upon the Church’s authority or its procedure. To be sure, the Church’s authority is presumed at the end, but the foregoing is not about Church procedure at all. It is about the steps to be taken by one who has been sinned against by a brother or sister.
The road described is about how he attempts to find reconciliation with his brother: he seeks privately to gain acknowledgement and repentance from the fault (18:15). If the brother does not repent, he then takes witnesses (18:16), which could refer to those observing the attempt, or alternatively may refer to others who witnessed the brother’s original sinful action.
It is only when these (private, non-ecclesiastical) efforts at reconciliation fail that the matter is brought before the Church (18:17). The steps to be taken by the Church are not described at all; it is only assumed that the Church will address the erring brother to call him to repentance, since the subsequent disfellowshipping occurs if he “will not listen.”
I note all this simply to point out that Matthew 18 is not about the process of church discipline, which will in fact vary according to circumstances. Some people suppose that somehow Matthew 18 mandates that church discipline is only properly carried out if there is a process involved. But Matthew 18 indicates no such thing. Although presumably the Church takes some time to listen to the complainant and verify the complaint, the passage indicates no back and forth or series of meetings.
Now, note: This is not to say that such a process should never occur; in many cases, wisdom would dictate that it should. But you cannot derive that from Matthew 18.
The character and process of church discipline ought to be dependent upon the character of the sin and the posture of the sinner.
If the matter is a private complaint between two individuals, the church should inquire whether the complaining party has undertaken the steps described in Matthew 18; it should not be involved unless that has occurred. If the things go well in such a case, the church will never be involved at all. Reconciliation will occur in private.
If, however, the matter in view is not a private complaint, the story is very different. In 1 Corinthians 5, for example, Paul performs an excommunication in absentia without so much as talking to the sinner in question. The sin was heinous and public, and in Spirit-led wisdom, he took swift and unequivocal action.
Of course, in real life, situations will run the gamut between those two poles. The Church is called to love and protect all its members, to reach out to the wayward, and to maintain the purity of the table. The severity of the situation, whether the sin is public or not, what sort of stumbling block the sinner is creating for his brothers and sisters, whether the characteristic attitude is humility or haughtiness, whether the sin is one of weakness or otherwise—all these factors enter into the question of how long and how firmly the Church ought to act.
And when all is said and done, and a recalcitrant sinner is evicted, then the pattern of 70×7 (18:21–22) still applies. Just as the individual must forgives sins 70×7, so too the Church should be eager to display grace in restoring those who repent.