Doctrine & Covenants 138:57-59

I beheld that the faithful elders of this dispensation, when they depart from mortal life, continue their labors in the preaching of the gospel of repentance and redemption, through the sacrifice of the Only Begotten Son of God, among those who are in darkness and under the bondage of sin in the great world of the spirits of the dead. The dead who repent will be redeemed, through obedience to the ordinances of the house of God, and after they have paid the penalty of their transgressions, and are washed clean, shall receive a reward according to their works, for they are heirs of salvation.