Else what shall they do who are baptized for the dead, if the dead rise not at all? why are they then baptized for the dead?
All Commentaries on 1 Corinthians 15:29 Go To 1 Corinthians 15
Ambrosiaster
AD 400
It seems that some people were at that time being baptized for the dead because they were afraid that someone who was not baptized would either not rise at all or else rise merely in order to be condemned. Commentary on Paul’s Epistles.