A revelation on excommunication had been recently received by Alma (Mosiah 26:29-32). Its implementation at this crucial time allows for the preservation of the church in Zarahemla. Imagine what would have happened if this growing crowd of dissidents were allowed to remain as members. They would continue to influence the weakest of the members and become a festering cancer amongst the faithful. The proper process of excommunication is more than just cleansing the inner vessel, it preserves the integrity of the church, protects the weaker members, and allows the church to move forward. Spiritually speaking, however, excommunication is a tragedy for the individual soul.
Spencer W. Kimball
"The scriptures speak of Church members being 'cast out' or 'cut off,' or having their names 'blotted out.' This means excommunication. This dread action means the total severance of the individual from the Church. The person who is excommunicated loses his membership in the Church and all attendant blessings. As an excommunicant, he is in a worse situation than he was before he joined the Church. He has lost the Holy Ghost, his priesthood, his endowments, his sealings, his privileges, and his claim upon eternal life. This is about the saddest thing which could happen to an individual. Better that he suffer poverty, persecution, sickness, and even death. A true Latter-day Saint would far prefer to see a loved one in his bier than excommunicated from the Church. If the one cut off did not have this feeling of desolateness and barrenness and extreme loss, it would be evidence that he did not understand the meaning of excommunication.
"An excommunicant has no Church privileges. He may not ... partake of the sacrament, serve in Church positions, offer public prayers, or speak in meetings; he may not pay tithing except under certain conditions as determined by the bishop." (Miracle of Forgiveness, p. 100)