Early Church Fathers on being justifiied by faith
Ignatius of Antioch
"His cross, and his death, and his resurrection, and the faith which is through him, are my unpolluted muniments; and in these, through your prayers, I am willing to be justified (Epistle to Philadelphians). [Note: “muniments” are title deeds, documents giving evidence of legal ownership of something.]
Athanasius
It would, of course, have been unthinkable that God should go back upon His word [Genesis 2:17] and that humanity, having transgressed, should not die. it was unthinkable that God, the Father of Truth, should go back on His word regarding death [Genesis 2:17] in order to ensure our continued existence. He could not make Himself a liar. What, then, was God to do?. The Logos perceived that our perishing condition could not abolished except through death. Yet He Himself, as the Logos, being immortal and the Father’s Son, could not die. For this reason, therefore, He assumed a body capable of death, in order that this body, through belonging to the Logos Who is above all, might become a sufficient exchange in dying for all. His body, remaining imperishable through His indwelling, would thereafter put an end to perishing for all others as well, by the grace of the resurrection. By surrendering to death the body which He had taken, as an offering and sacrifice free from every stain, He immediately abolished death for His human brothers by the offering of the equivalent. For naturally, since the Logos of God was above all, when He offered His own temple and bodily instrument as a substitute for the life of all, He fulfilled by death all that was required. (On the Incarnation of the Logos, 6-7, 9)
To provide against this also, He sends His own Son, and He becomes Son of Man, by taking created flesh; that, since all were under sentence of death, He, being other than them all, might Himself for all offer to death His own body; and that henceforth, as if all had died through Him, the word of that sentence might be accomplished (for all died in Christ), and all through Him might thereupon become free from sin and from the curse which came upon it, and might truly abide for ever, risen from the dead and clothed in immortality and incorruption. (Athanasius, Orations Against The Arians 2:69)
For man, being in Christ, was quickened. For this was why the Word was united to man, namely, that against man the curse might no longer prevail. This is the reason why they record the request made on behalf of mankind in the seventy-first Psalm: Give the King Your judgment, O God (Psalm 72:10): asking that both the judgment of death which hung over us may be delivered to the Son, and that He may then, by dying for us, abolish it for us in Himself. This was what He signified, saying Himself, in the eighty-seventh Psalm: Your indignation lies hard upon me (Psalm 88:7). For He bore the indignation which lay upon us (On Luke 10:22, ch.2)
Clement of Rome
“We also, being called through God’s will in Christ Jesus, are not justified through ourselves, neither through our own wisdom or understanding, or piety, or works which we have done in holiness or heart, but through faith” (Epistle to Corinthians).
Polycarp
"I know that through grace you are saved, not of works, but by the will of God, through Jesus Christ (Epistle of Philippians).