In Mormonism, a sealing is an ordinance usually performed in temples whereby families are bound together in a family relationship which Latter-day Saints believe will endure beyond physical death. This is the doctrine which lies behind the LDS slogan, "Families are Forever."

A sealing is performed either as a covenant marriage between a man and a woman, or as a sealing of children to their parents. A sealing of a man and woman is also called a "temple marriage" or eternal marriage.

Unlike traditional, civil marriages, which LDS faithful believe are dissolved at death, Latter-day Saints believe that a couple who has been sealed "for time and all eternity" will be married beyond physical death.

The LDS church recognizes other monogamous, heterosexual marriages, both civil and religious, although they believe that such marriages will not continue after death because "Eternal Marriages" must be performed by a Priesthood authority. However, "Eternal Marriages" are also performed vicariously for the deceased so that once all the prior temple ordinances are completed for a deceased individual, couples who were not sealed during their life may be sealed to each other and their children by proxy.

Couples who have children born to them before the couple is sealed, may have their children sealed to them after the couple is sealed. Couples who have children after being sealed do not have to have their children sealed to them in a separate ceremony. Latter-day Saints refer to children born to sealed parents as being "born in the covenant" and are automatically sealed to their parents.

Divorce rates for sealed couples were reportedly far lower than national rates for decades but have risen significantly over the last several years. Although a divorce legally dissolves a civilly-recognized marriage, the Church still recognizes a sealed couple as being sealed. A couple who has been sealed may have their sealing "cancelled", but this is uncommon, occurs only under special circumstances and is only granted by the highest LDS officials. Some refer informally to a "cancellation" as a “temple divorce”, but the terminology designated by Church leaders is "cancellation of a sealing".

A cancellation typically follows after a civil divorce and when the woman then seeks to be sealed to another man. Some have criticised the LDS church for allowing a man to be "sealed" to multiple wives while a woman can be "sealed" to only a single man, and some further argue this is tacit approval of the LDS church's purportedly abandoned practice of plural marriage. [1]

In other cases cancellation is implied if one of the partners to the marriage is excommunicated, for example, because of adultery or serious spousal abuse.

The LDS church’s policy on sealings and cancellations reflect its doctrine of plural marriage although that doctrine is currently prohibited from being practiced in the Church: a man can be sealed to multiple women, but women can only be sealed to one man. A man sealed to one or more women, but civilly divorced or a widower, may be sealed to another woman assuming the couple is worthy and the union is permitted by Church authorities. Although a woman can only be sealed to one man, she can be married civilly to another man and have that marriage recognized by the Church.

The union of a sealed couple is regarded as valid only if both individuals have kept their religious commitments and followed LDS teachings. A sealed couple who have successfully kept their religious covenants, and whose sealing remains in force after death is said to have their sealing “sealed by the Holy Spirit of Promise”. The sealing of a sealed couple whose union has been disrupted by a civil divorce (amicable or acrimonious) is not likely to remain in force; it is more likely that either or both individuals have not successfully kept their religious commitmements. Just as deceased individuals may refuse any temple ordinance (such as a sealing) done by proxy on their behalf, couples, parents and children who were sealed to each other during their own life may exercise their agency to refuse to accept a sealing of which they were a part. No one will be sealed to any one with whom they do not want to be sealed.

Since the LDS church rejects same-sex marriages, these unions are not performed in temples nor recognized by the LDS church.

See also: Eternal Marriage