When a man is excommunicated from the Mormon Church, does he lose his priesthood, or just have the right to use it withdrawn? We know he cannot participate in church meetings, partake of the sacrament, hold callings, etc., but is the right to preside in his own home also taken away? Can he no longer preside over his family during Family Home Evenings? Can he no longer offer family prayers at home? How does the church force them to stop wearing their temple garments when they’ve been excommunicated? Who’s going to stop them? Your insight into these things would be much appreciated.
When a person is excommunicated from the Mormon Church, he is no longer a member of the Church. He has no priesthood. It has been revoked. About presiding in the home, he is still a member of his household by civil authority, and in that authority he still presides over his home and would have the right to direct all its activities, hopefully in justice and righteousness. He may call the family together for family home evening, direct family prayers and the blessings on the food, encourage his family to participate in their religious activities and accompany them to church. As a non-member he may not act in any official capacity in the Church that would require priesthood authority.
Concerning the wearing of the sacred temple garment, the Mormon Church does not use force in any of its operations; that is a tool of Satan, not of the Lord. The ex-communicant is directed to not wear the temple garment. If he chooses to wear it anyway, it will be a curse to him rather than a blessing, and if he comes to his senses he will soon discard it.
The purpose for excommunication is two-fold. First, its purpose is to assist the person in the repentance process. The ex-communicant is encouraged to return to church and to participate in the fellowship of the saints. He may be asked meet regularly with the bishop or other church officials for counsel, advice and encouragement. If true repentance is demonstrated he may apply for re-baptism, but such a baptism is not performed until at least a year after excommunication. If the person is baptized, again, normally after at least a year of membership his priesthood may be restored to him. That restoration is accomplished by a General Authority under the direction of the President of the Church.
The other purpose for excommunication is to protect the Church from those members who under the influence of the adversary become enemies of the Church and attempt to do it harm. Without priesthood authority and the guidance of the Holy Spirit their influence is vastly truncated, and they fade away into oblivion.