Downthumber should probably explain himself or herself, with authorities and citations of their own. St. Augustine is one of those who argued strongly against Apocatastasis; yet he nevertheless regarded those who held views that a great many (even if not absolutely all) would attain Salvation (and the Bible too suggests they finally will in Rev 7:9, "a great multitude that no man could number" in Heaven) as "Compassionate Christians". He argues against it, and he makes the now familiar distinction between venial sin and mortal sin, and Purgatory and Hell, because of it. But many Early Christians held variants of Apocatastasis, including those whose sanctity cannot be doubted, like St. Clement of Alexandria, St. Jerome, St. Gregory of Nyssa, and likely St. Gregory nαzιanzen as well, as the CE explains.
"Tixeront also writes very aptly concerning this matter: "Clement allows that
sinful souls shall be sanctified after death by a spiritual fire, and that the wicked shall, likewise, be punished by fire. Will their chastisement be eternal? It would not seem so. In the Stromata, VII, 2 (P.G., IX, col. 416), the punishment of which Clement speaks, and which succeeds the final judgment, constrains the wicked to repent. In chapter xvi (col. 541) the author lays down the principle that
God does not punish, but corrects; that is to say that all chastisement on His part is remedial. If
Origen be supposed to have started from this principle in order to arrive at the apokatastasis--and
Gregory of Nyssa as well--it is extremely probable that
Clement of Alexandria understood it in the same sense" (Histoire des dogmes, I, 277) ...
It was through
Origen that the
Platonist doctrine of the apokatastasis passed to
St. Gregory of Nyssa, and simultaneously to
St. Jerome, at least during the time that
St. Jerome was an
Origenist. It is
certain, however, that
St. Jerome understands it only of the
baptized: "In restitutione omnium, quando corpus totius ecclesiæ nunc dispersum atque laceratum, verus medicus Christus Jesus sanaturus advenerit, unusquisque secundum mensuram fidei et cognitionis Filii Dei . . . suum recipiet locuм et incipiet id esse quod fuerat" (Comment. in Eph., iv, 16; P.G., XXVI, col. 503)."
St. Jerome applies it to all Baptized Christians. St. Robert Bellarmine, without adopting such a view, mentions that St. Jerome and other Early Fathers held to such opinions. It's interesting and probably not very well known that they did.