LDS: temple sealing

Mormons believe that the sacred ordinance of marriage is God-ordained and is meant to seal together family units, including the parents and all natural and legally adopted children.

The divine plan of happiness enables family relationships to be perpetuated beyond the grave. Sacred ordinances and covenants available in holy temples make it possible for individuals to return to the presence of God and for families to be united eternally. - The Family: A Proclamation To The World 1995

Under most circumstances, adopted children may be sealed to the adoptive parents in an LDS temple. However, living children born in the covenant, that is, born to parents who have been sealed to each other in an LDS temple, cannot be sealed to any other parents although they can be adopted for life; and children who have been previously sealed to another couple may not be sealed to adoptive parents without cancellation of the former sealing. The temple sealing of a living adopted child into an eternal family relationship is performed only after legal adoption is finalized in accordance with local law (General Handbook of Instructions, Salt Lake City, 1989, 6-6). - Encyclopedia of Mormonism, Vol. 1, Adoption of Children, Macmillan Publishing, 1992

Forum Discussion on Sealing of Adopted Children