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 (Mt. 18:19)
The poll which started this series was done quite some time ago. Thus, especially for this verse, I took some time to recollect the exact reason why it was placed in the poll in the first place. This is since the previous verse Mt. 18:18 is just as abused as verse 19, especially in the sacerdotal and charismatic circles.
After some thought, I have decided to exegete both verses plus verse 20 and address the abuse of all three texts in this one post, so here goes.
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. (Mt. 18:18-20)
“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.” (Mt. 18:15-20)
Mt. 18:18-19 is situated in the context of verses 15 to 20 — a passage primarily focused on the issue of conflicts in the Church due to personal sin against another. The larger Matthean context for this passage is the issue of people and relationships, and thus verses 15-20 focuses on the aspect of conflicts within the Church.
In verse 15, Jesus starts narrating to us the scenario of such an interpersonal conflict. This conflict is not caused by doctrinal errors of any sort, which are treated differently and more severely (cf 1 Tim. 5:19-20, Titus 1:13b; 3:10), but rather of personal practical sin of one Christian against another ("sins against you"). Such sins are non-public in nature since if they are public, then by definition the offender would have sinned against many people in public, whereas the context here talks about personal sin.
In the context of such personal and private offences, the offence should be settled privately and personally. Verse 15b calls one to tell him his fault and settle the issue between the both of you. Obviously, this is to be done with love as all other actions are to be (Mt. 22:39, Jn. 13:34), but the issue must be resolved, not glossed over.
Verse 16 continues our Lord's dictate in the case when such a person refuses to listen and repent of his sin. Such a one is to be confronted by two or more people being there as witnesses. This is to create witnesses of the obstinate brother's unwillingness to repent is such was to happen, and also to ascertain whether it is indeed true that the fault lies in the other brother's unrepentance. Verse 17 continues with the scenario that such a brother is still unwilling to repent. The whole church is then brought in to exhort him to repent. Further unrepentance causes the judgment of the church to be passed on the person, and he is to be regarded as an unbeliever not to be fellowshipped with but to be called to repentance as if he is an unbeliever, yet in so doing with the hope that he finally repents and is saved (1 Cor. 5:5).
It is in this context that verses 18-20 are to be interpreted. Verse 18 follows verse 17 and thus the subject matter is with regards to church discipline. Binding someone is accomplished by church discipline and excommunication from the Church due to his unrepentant sin, while loosing is the converse act of accepting the penitent back after he has repented of his sin (cf. 2 Cor. 2:5-8). The binding and loosing in verse 18 operates therefore with regards to being inside and outside the Church. The Church is to to represent Christ on this earth (1 Tim. 3:15, Eph. 2:20; 3:10 cf Acts 15:6, 1 Tim. 3:1-5), and thus what the Church does is to be like as if Christ Himself has actually pass the same judgment. The judgment of binding and loosing by the Church is to therefore function as if Christ Himself has actually did the same.
Practically, this means that someone who is legitimately excommunicated from the Visible Church is de facto similarly not regarded as being in the Invisible Church of believers, and apart from repentance, such a one is lost. Unrepentant excommunicated professed Christians therefore prove themselves to be not true believers at all, since true believers are saved while unrepentant excommunicated professed Christians are not.
In this modern time with high mobility and low church and denomination affiliation bonds, the text of Mt. 18:18 should sober us Christians. The idea that one is fine merely by changing church at the first sign of trouble, or that even after being excommunicated one can join the next church down the road who will welcome him with open arms, goes against the plain teaching of the Scriptures here. The latter attitude, especially if one scorns the legitimate sentence of excommunication from a true church, may well be a symptom that one is in fact unregenerate and not saved. With regards to the former, if in fact this passage teaches anything at all which we must remember, it is that conflicts of any kind with fellow believers should be attempted to be resolved, and that leaving at the first sign of trouble is not the Christian way.
This correlation between the judgments of Christ and the church occurs only when the judgments are legitimate and true according to the proper application of God's Word, for God does not contradict Himself. The Pharisees who function as the rulers of the OT church wrongly threw out the man born blind (Jn. 9:34-35), which shows that false judgments by the church are not binding and are no more correlated with the judgments of Christ than the Phariseees' judgments were.
Mt. 18:18 thus does not teach sacerdotalism, or the belief that the Church or the leaders of the Church (Bishops, Priests etc.) function in some sense as mediators between God and the normal laity. In fact, Jn. 16:2 teaches us that false judgments by people who claim to act on behalf of God in the church would happen, thus falsifying sacedotalism. Mt. 18:18 teaches the work of the Church when she functions exactly as how she should be functioning as the representative of Christ, and her judgments are to be treated seriously as true and binding on all Christians insofar as they are true and legitimate according to the Scriptures, and are to be ignored if they are not. Scripture's message to the modern "church shoppers" therefore is that judgments of the Church are to be taken seriously, while its message to the sacerdotalists is that such judgments are not true by fiat and thus they do they act ex opere operato.
A most appalling eisegesis of verse 18 can be heard in some charismatic circles which couple verse 18 together with Mk. 3:27, and then appropriate this verse for the purpose of spiritual warfare. Needless to say, the context is not even close to the topic of spiritual warfare, so wrenching this verse out of context and connecting it to Jesus' teaching of the binding of the strong man (which depict Satan) is definitely in error.
Verses 19-20 are two verses that have been used as an encouragement for prayer, especially in teaching us how God will be with us in corporate prayer since "two or three are gathered" in His name as per the dictates of Mt. 18:20 so He will hear our prayers.
Now, certainly praying together with other believers is definitely good and is in fact taught in Scripture (cf Acts 2:42. See the numerous examples in the OT of corporate prayer), but that is not what the passage here is teaching in context. Verse 18 is on the subject matter of the judgments of the Church and church discipline. Verses 19-20 therefore are telling us that God will be with His church as they pray for His wisdom and will be with them as they pass out the judgments of the church. It is a promise of God to His Church that He will be with them in their judgments and deliberations as they pray to Him in this regard. Following on with the "representative of Christ" idea as seen in verse 18, this means that the promise is not meant to function ex opere operato ("will be done for them"), as if God will rubber stamp whatever proceedings and judgments that the Church passes, but that the Church when functioning properly will experience God's promise of His aid and presence among us in this regard.
Such being the case, Mt. 18:19-20 cannot exactly be used to promote prayer except in a very loose inferred sense. To use them as proof-texts to promote corporate prayer is therefore not optimum.