Mormons believe that individuals who have died can hear and receive the gospel of Jesus Christ in the spirit world. And through proxy baptism performed for them in an LDS temple, they can attain eternal life in the presence of God.
The important question here is – does baptism for the dead have a basis in the Bible? Was this Mormon temple rite originally established by Jesus, and taught and practiced by His apostles?
LDS believe the ordinance of baptism for the dead was practiced in the early church, because the Apostle Paul mentions it in 1 Corinthians chapter 15, verse 29 “Else what shall they do which are baptized for the dead, if the dead rise not at all? Why are they then baptized for the dead?”