Upvote:2
Clement of Alexandria (AD 155 to 220) a teacher of Origen, taught the doctrine of apocatastasis.
Origen (AD 185 to 254) apparently believed that eventually everyone, including the Devil, would be saved.
Gregory of Nyssa- (AD 335 to 394) espoused universal salvation as supported by Origen.
Apocatastasis was taught by Gregory of Nyssa, Clement of Alexandria, and Origen, but it is not a doctrine derived from a pure study of Scripture. Holding such a position requires mental gymnastics and blatant disregard for the plethora of passages that teach otherwise.
John 3:16–18, Matthew 25:41, 46, and 1 John 5:12 explicitly define the difference between those who “have life” and those who are condemned. John 3:36, in particular, makes it clear that “whoever believes in the Son has eternal life; whoever does not obey the Son shall not see life, but the wrath of God remains on him.” Universalists contend that the word remains means “remains until some future date when it is lifted.” But that is human conjecture and not a faithful interpretation of the text. “Remains” means what it says. God’s wrath remains where disobedience remains (Romans 1:18; 2:5; Colossians 3:6; Ephesians 5:6). There are no second chances after death, according to Hebrews 9:27.
Upvote:3
KJV 1 Peter 4:1-6, but especially verse 6, might have a bit of an answer about this idea in the decades after Christ left the earth.
6 For for this cause was the gospel preached also to them that are dead, that they might be judged according to men in the flesh, but live according to God in the spirit.
To me that means that the basic doctrinal text of Christianity doesn't entirely preclude the notion. The prime example of teaching this doctrine would actually be Peter.
Whether or not pre-500 orthodox clergymen actually taught it as Peter said it is obviously going to be less common. I don't know any specifics.
I would count being able to come to Christ and learn of Him postmortem to be about as good as baptism as you can get when you're dead, since most Christians' definition of the afterlife and what we can do in it are really fuzzy.
However, the only specific denomination of Christianity I know of that practices any sort of proxy ordinance for the dead (baptism being the first) is the Church of Jesus Christ of Latter Day Saints.
Cit: I'm a member.