Moreover, from the time when He said, 'Except a man be born of water and of the Spirit, he cannot enter into the kingdom of heaven;' and again, 'He that loseth his life for my sake shall find it; ' no one becomes a member of Christ except it be either by baptism in Christ, or death for Christ.
Saint Augustine of Hippo (2016). “Saint Augustine of Hippo Collection [50 Books]”, p.739, Aeterna Press