If a man (or, a woman) ran off with another’s mate, could he be forgiven and accepted back into the Christian congregation?

This sort of thing occurs with some frequency among those not trying to live by Bible standards. By comparison, it is infrequent among those associated with Jehovah’s people, which makes it more shocking if it does occur. Still, there is no need to think that a case like this should be handled according to some human rule. As with other sins, before such a person could be accepted by God and his people, the sinner would have to repent and show clearly fruits of repentance.

God’s dealings with the Israelites indicate his forgiveness, at times, of even shocking and persistent sin. (Deut. 4:30; Isa. 55:7; 57:16-18; Zech. 1:3, 4) Jesus mentioned the “joy in heaven over one sinner that repents.” Then he illustrated the point with the story of the prodigal son who squandered his money on debauched living with harlots. When the son came to his senses, returned and sought forgiveness for sinning against both heaven and his father, the father warmly forgave him.​—Luke 15:1-7, 11-24.

Yet, the Bible also shows that a Christian who sins and does not repent should be expelled from the congregation in order to keep it spiritually pure. (1 Cor. 5:1-5, 11-13) That happened to a man in Corinth who openly lived an immoral life. The Scriptures indicate that in order for him to be accepted back into the congregation such a man would have to repent, reject his immoral course, turn around and produce fruit befitting repentance. Apparently he did so soon afterward. In Second Corinthians, thought to have been written less than a year later, the apostle Paul urged the congregation to forgive a sinner, evidently referring to that disfellowshiped man who must have repented.​—2 Cor. 2:5-10; Matt. 3:7, 8; Acts 26:20.

This Scriptural disfellowshiping procedure is employed by congregations of Jehovah’s Witnesses today, also. And in accord with this example, there is no set length of time before reinstatement; it awaits genuine repentance, which may even take years.

The committee of elders handling such a request for reinstatement would want to give thought to the difference between a person who succumbs to sin in a moment of weakness and someone who conspires to sin. We can recall that God showed mercy to Peter after he denied Jesus three times; yet God executed Ananias and Sapphira, who schemed in their hearts how to carry out their deceit.​—Acts 5:1-11.

Elders thus need to exercise great caution in cases where hypocritical pretense and conspiracy are involved. A person may profess sorrow and repentance, but if he were back where he started, would he “do it all over again”? Would he leave his mate for another? Of course, now he has entered a new marriage and so cannot simply end it and return to the way things were before; the former marriage ended with the divorce, adultery and remarriage. (Matt. 19:9) Yet, does he manifest genuine repentance, being “crushed” and cut to the heart? (Isa. 57:15) Does he have a repulsion for the sin he committed, rather than mere sorrow that he is disfellowshiped and is not able to enjoy Christian association? Has he over a sufficient period of time, which is not predetermined, produced the fruit that befits repentance? The elders would need to be convinced, without a doubt, that there is true repentance. If they do not sincerely feel confident on this, they may decide to wait and meet again to review the matter after more evidence has accumulated.

The elders should feel keenly their responsibility to protect the congregation, yet always being conscious of God’s mercy and desire that persons gain life. (Rom. 2:4) They realize that they do not have superhuman ability to read hearts and motives perfectly, as does Jehovah, to whom the sinner is accountable. (Heb. 4:13) So they will strive to guide their consideration and decision by God’s Word and what they can determine as to the disfellowshiped person’s attitude and heart condition. If in time the committee of elders should conclude that the sinner has truly repented and worked to purify his heart, reinstatement is in order, even as occurred with the man in Corinth. (Jas. 4:8) But there is no set time for that to take place.