"If your brother sins against you, go and tell him his fault between you and him alone."
Fraternal charity is a demand of the Gospel: "Love one another as I have loved you". An expression of charity is the correction made necessary sometimes by concern for the salvation of a brother or sister. This is the root
Communication deficiencies often lie at the root of troubled relationships. This can be true of any two or more people who must work, live or perform any task together, in any situation, but are most visible in the separations and divorces so tragically common among married couples today.
Persons approach conflict out of their experiences and prejudices, whether good or bad, helpful or unhelpful. A tendency to react with anger or emotions in thE face of conflict can prevent open communication on the part of the other and who might react by closing up in self defense, preventing communication. Reacting with silence, on the other end of the spectrum, can leave the other blissfully unaware that a problem exists, while one's resentments and conflicts continue to build up until they threaten to explode.
The love we owe to everyone, no matter the nature of their relationship with us, is to seek their salvation. This charity under certain circumstances will demand the service of the fraternal correction to which the Lord urges us in the Gospel.
"The fruits of charity are joy, peace, and mercy; charity demands beneficence and fraternal correction; it is benevolence; it fosters reciprocity and remains disinterested and generous; it is friendship and communion: Love is itself the fulfillment of all our works. There is the goal; that is why we run: we run toward it, and once we reach it, in it we shall find rest." (CCC 1829)
All of us are in need of conversion because all of us are sinners. We should respond with gratitude when another makes us aware that something for which we are responsible stands between us and our salvation.
"Conversion is accomplished in daily life by gestures of reconciliation, concern for the poor, the exercise and defense of justice and right, by the admission of faults to one's brethren, fraternal correction, revision of life, examination of conscience, spiritual direction, acceptance of suffering, endurance of persecution for the sake of righteousness. Taking up one's cross each day and following Jesus is the surest way of penance." (CCC 1435)
"If he listens to you, you have won over your brother."
We may be personally responsible for fraternal correction when a particular fault on the part of another affects us personally and we certainly rejoice when someone returns to the right way and continues to walk in friendship with us. We are not, however, responsible if our brother or sister refuses our correction and rejects our gesture of charity. And another's friendship with Christ is, it hardly need be said, more important than their friendship with another human being.
If a sin is private in nature every effort should be made to keep it such, both to more easily preserve the good reputation and easily smooth the way for the conversion of the sinful party as well as to avoid the sin of detraction on the part of others.
If a sin is public then public correction may be necessary.
"If he does not listen, take one or two others along with you, so that 'every fact may be established on the testimony of two or three witnesses." There are cases where we might be called to involved a third party but these should be rare and perhaps only in cases where the community is adversely affected by the disruptive or uncharitable behavior of one of its members.
There are cases where something akin to excommunication may be imposed for the health of teh community, asking someone to separate from the body until they are willing to amend their loves for the sake of their own and the common good. 'If he refuses to listen to them, tell the church. If he refuses to listen even to the church,then treat him as you would a Gentile or a tax collector."
All of these measures are medicinal, that is, ordered toward the salvation of everyone involved and this should be kept in mind at all times, as "salvation is the highest law of the Church".
"Punishment has the primary aim of redressing the disorder introduced by the offense. When it is willingly accepted by the guilty party, it assumes the value of expiation. Punishment then, in addition to defending public order and protecting people's safety, has a medicinal purpose: as far as possible, it must contribute to the correction of the guilty party." (CCC 2266)