“”if I understand the argument-whether someone can lose their salvation. I’m saying that the historical evidence shows that church fathers never taught this and that the Church (East and West)””
Perhaps you should read these ones
“Christ shall not die again in behalf of those who now commit sin, for death shall no more have dominion over Him; but the Son shall come in the glory of the Father, requiring from His stewards and dispensers the money which He had entrusted to them, with usury; and from those to whom He had given most shall He demand most. We ought not, therefore, as that presbyter remarks, to be puffed up, nor be severe upon those of old time, but ought ourselves to fear, lest perchance, after [we have come to] the knowledge of Christ, if we do things displeasing to God, we obtain no further forgiveness of sins, but be SHUT OUT FROM HIS KINGDOM. And therefore it was that Paul said, ‘For if [God] spared not the natural branches, [take heed] lest He also spare not thee, who, when thou wert a wild olive tree, wert grafted into the fatness of the olive tree, and wert made a partaker of its fatness.’” Irenaeus, Against Heresies, 4:27:2 (A.D. 180
“[T]hat eternal fire has been prepared for him as he apostatized from God of his own free-will, and likewise for all who unrepentant continue in the apostasy, he now blasphemes, by means of such men, the Lord who brings judgment [upon him] as being already condemned, and imputes the guilt of his apostasy to his Maker, not to his own voluntary disposition.” Justin Martyr, fragment in Irenaeus’ Against Heresies, 5:26:1 (A.D. 156).
“It is the Spirit then which is in God, and not we viewed in our own selves; and as we are sons and gods because of the Word in us, so we shall be in the Son and in the Father, and we shall be accounted to have become one in Son and in Father, because that that Spirit is in us, which is in the Word which is in the Father. When then a man falls from the Spirit for any wickedness, if he repent upon his fall, the grace remains irrevocably to such as are willing; otherwise HE WHO HAS FALLEN IS NO LONGER IN GOD because that Holy Spirit and Paraclete which is in God has deserted him), but the sinner shall be in him to whom he has subjected himself, as took place in Saul’s instance; for the Spirit of God departed from him and an evil spirit was afflicting him.” Athanasius, Discourse Against the Arians, 3:25 (A.D. 362).
“Let us admonish each other. Let us correct each other, that we may not go to the other world as debtors, and then, needing to borrow of others, suffer the fate of the foolish virgins, and FALL from immortal salvation.” John Chrysostom, Concerning Statues, 21 (A.D. 387).
“It is, indeed, to be wondered at, and greatly to be wondered at, that to some of His own children—whom He has regenerated in Christ—to whom He has given faith, hope, and love, God does not give perseverance also.” Augustine, On Rebuke and Grace, 18 (A.D. 427).