Summary: In every church in Christendom, we will eventually be confronted with some great personal offenses.
Prelude, Purpose, Plan
In every church in Christendom, we will eventually be confronted with some great personal offenses. How can we better deal with major conflict? Is conflict resolution always possible or even realistic? What can we do when our grievances are ignored? Why is conflict a part of life? Let’s look at Matthew 18:15-20 and learn some broad principles of working through great personal offenses.
The Setting of Matthew 18:15-20
Let’s remember that the setting in Matthew 18:15-20 is a time when the disciples were the Church. After the resurrection, the house church became the norm. Megachurches, such as the assembly on Pentecost, were and still are rare exceptions. So, taking most disputes to the whole church is not literally possible in larger assemblies, but the spirit of these instructions is applicable in many wonderful ways. Conflict will always be part of church life, as long as sin exists. Sometimes we can resolve things easily and sometimes we must separate for a time, like Barnabas and Paul (Acts 15:36-39) or the universal Church and our schisms through Christian history.
Matthew 18:15 Great Personal Offense
In Matthew 18:15 Jesus taught, “if your brother sins against you, go and tell him his fault between you and him alone.” The wording is softened in most English translations. The sense in the original language is much stronger, such as to “convict him of his fault.” Today we might say if you’ve got to berate someone, do so privately rather than castigate them in public. It’s the kind of thing we might try to do behind closed doors. It’s not talking about everyday personality conflicts. In those cases we bear with one another (Colossians 3:13; Ephesians 4:2). In this case the offense is personal and major.
 Ellicott's Commentary for English Readers
Most of the time we forbear one another’s weaknesses. It’s no use creating an argument over every minor infraction. Some churches may have such an intolerably authoritarian atmosphere of fear, but that’s not how knowledgeable Bible students know church should be. Forgiveness and forbearance of each other’s faults makes a church more joyful. But does that mean that we should never say anything? There is a legitimate time to speak and Jesus seems to indicate that when a sin is directed at us, personally, then we may cautiously act. In fact, Jesus recommends going to our brother alone over a personal offense. “If he hears you, you have gained your brother.”
Matthew 18:16 Escalation
In Matthew 18:16 we read that after talking to someone privately about a personal offense, “if he will not hear, take with you one or two more, that ‘by the mouth of two or three witnesses every word may be established.’” The principle of two or three witnesses is Jesus’ recognition a legal obligation in the Old Testament (Deuteronomy 17:6; Deuteronomy 19:15). This step escalates the situation way beyond a simple personal offense. The purpose of these extra friends or perhaps even people familiar with the situation is probably to convince a person of their fault, and even to witness their response of willingness or unwillingness to change.