Clement:
Whosoever will candidly consider each particular, will recognise the greatness of the gifts which were given by him. For from him [i.e. Abraham] have sprung the priests and all the Levites who minister at the altar of God. From him also [was descended] our Lord Jesus Christ according to the flesh. (Romans 9:5) From him [arose] kings, princes, and rulers of the race of Judah. Nor are his other tribes in small glory, inasmuch as God had promised, “Your seed shall be as the stars of heaven.” All these, therefore, were highly honoured, and made great, not for their own sake, or for their own works, or for the righteousness which they wrought, but through the operation of His will. And we, too, being called by His will in Christ Jesus, are not justified by ourselves, nor by our own wisdom, or understanding, or godliness, or works which we have wrought in holiness of heart; but by that faith through which, from the beginning, Almighty God has justified all men; to whom be glory for ever and ever. Amen. (St. Clement’s Epistle to the Corinthians, c. 32)
ANSWER:
But there are two things that must be noted. First, St. Clement is here making the same claim St. Paul makes in Romans 4, that what made Abraham right with God was not works of the law, but faith. St. Clement is not in this paragraph speaking about growing in righteousness, but about being transferred from the state of sin into which we are born as a result of the sin of the first Adam, to the state of grace and to the adoption of the sons of God through the second Adam, Jesus Christ. St. Clement is saying here that justification (in this sense) is not by our own works or by the righteousness we have wrought or by our wisdom or our understanding or our godliness or by works we have done in holiness of heart, but by faith.10
The second thing that must be kept in mind is the nature of this faith by which we are justified, whether it is living faith or dead faith. That is, is this a faith informed by the virtue of agape, or is it a faith not informed by the virtue of agape? In Catholic soteriology, agape is a virtue (i.e. habit) poured into our hearts by the Holy Spirit, as St. Paul says:
because the agape of God has been poured into our hearts through the Holy Spirit who has been given to us.” [ὅτι ἡ ἀγάπη τοῦ θεοῦ ἐκκέχυται ἐν ταῖς καρδίαις ἡμῶν διὰ πνεύματος ἁγίου τοῦ δοθέντος ἡμῖν] (Romans 5:5)
“For faith, unless hope and charity be added to it, neither unites man perfectly with Christ nor makes him a living member of His body. For which reason it is most truly said that faith without works is dead (James 2:17, 20) and of no profit, and in Christ Jesus neither circumcision availeth anything nor uncircumcision, but faith that worketh by charity. (Gal 5:6, 6:15)11
If any one saith that men are justified either by the sole imputation of the justice of Christ, or by the sole remission of sins, to the exclusion of the grace and the charity which is poured forth in their hearts by the Holy Ghost, and is inherent in them; or even that the grace, whereby we are justified, is only the favour of God; let him be anathema.12
https://www.calledtocommunion.com/2010/11/st-clement-of-rome-soteriology-and-ecclesiology/
In Catholic soteriology, only when faith is informed by the internal habit of agape in the soul is faith living faith, and hence justifying faith. The Council of Trent declared:
The saving faith of which St. Clement speaks is faith informed by agape, not faith uninformed by agape. We can see this in various places in his epistle. St. Clement writes:
On account of her faith and hospitality, Rahab the harlot was saved. (12)
Notice that it was not faith alone that saved her. The kind of faith that saved her was a faith working by agape. He continues:
Love unites us to God. Love covers a multitude of sins. Love bears all things, is long-suffering in all things. There is nothing base, nothing arrogant in love. Love admits of no schisms: love gives rise to no seditions: love does all things in harmony. By love have all the elect of God been made perfect; without love nothing is well-pleasing to God. (49)
For St. Clement the person without love is not united to God, and is therefore not justified. The person without love remains unforgiven. The person without love is not “well-pleasing to God”. So the person with faith alone, but lacking agape, is not justified.
St. Clement continues:
Blessed are we, beloved, if we keep the commandments of God in the harmony of love; that so through love our sins may be forgiven us. (50)
According to St. Clement, love is not merely an expression of gratitude that our sins are forgiven. Only by the presence of agape in us are our sins forgiven. Hence faith alone (so long as it is not informed by agape) does not justify.
St. Clement continues:
Abraham, styled “the friend,” was found faithful, inasmuch as he rendered obedience to the words of God.(10)
The faith of Abraham was a faith working through agape, not just mere faith.
St. Clement continues:
For what reason was our father Abraham blessed? Was it not because he wrought righteousness and truth through faith? (31)
For St. Clement the faith by which Abraham was blessed, was a faith informed by agape, and which thereby wrought righteousness. So these other places in St. Clement’s epistle explain how the passage in chapter 32 should be interpreted as referring to a faith informed by agape, not faith alone. This is also how St. Augustine understood justification by faith, as I recently showed here.13
Does St. Clement mean that it is faith alone that justifies, but that justifying faith is always accompanied by or followed by works of love? No, because faith-informed-by-agape is not identical to faith-followed-by-works. The whole point is what is inside the person. Yes, of course, what is inside will manifest itself outside, in our works. The person who claims to have faith but has no works, is deceiving himself. And what we do in exercising the grace and virtues that God has infused into our soul, leads to their growth in the soul. We cannot just kick back and rest in the presence of grace and virtues within. But, the important point is that faith and agape are virtues. They are supernaturally infused habits within the soul.
So the question is this: Why kind of faith justifies? Is it faith (i.e. the virtue) alone, or is it faith (i.e. the virtue) informed by agape (i.e. also a virtue). The Catholic answer is that the faith that justifies is a faith (i.e. the virtue in the soul) informed by agape (i.e. also a virtue in the soul). The Protestant answer is: faith alone [i.e. faith simpliciter, not faith-informed-by-agape] justifies, but this faith that justifies is always followed by agape and works.
If a person thinks of agape as fundamentally external or works (and misses the fact that agape is fundamentally a virtue), he would not accurately grasp the Catholic-Protestant disagreement. That is, if he thinks of agape only as an act (or only as an external act), he would conceive of faith-informed-by-agape as though it means faith-accompanied-by-good-works. But that is not what faith-informed-by-agape means, even though good works necessarily follow faith-informed-by-agape. The Catholic Church teaches that we are justified by living faith, and what makes faith living is agape (as a supernaturally infused virtue). What makes faith to be non-living, or dead, is the absence of agape (as a virtue). Dead faith does not justify; only living faith justifies.
Protestant theology tends not to give conceptual space to agape as a virtue, seeing it only as a work. Scott Clark, for example, denies that faith and agape are virtues. And that tends to lead to a misunderstanding on the part of Protestants, who think that when Catholics talk about faith-informed-by-agape, it means faith accompanied by works. If it meant that, then we could have no confidence that baptized babies who die before reaching an age in which they can do any works, could be saved. But, we believe that at baptism, the virtues of faith, hope, and agape are infused into the soul by the Holy Spirit, and therefore that the infant is justified at that very moment, because he now has faith-informed-by-agape, even though has not yet done a single good work.
So when St. Clement says the following:
Similarly we also, who by His will have been called in Christ Jesus, are not justified by ourselves or our own wisdom or understanding or godliness, nor by such deeds as we have done in holiness of heart, but by that faith through which Almighty God has justified all men since the beginning of time. Glory be to Him for ever and ever, amen.” (ch. 32)
The question is this: Is he talking about about living faith (i.e. faith informed by the virtue of agape), or is he talking about dead faith (i.e. faith where there is not the virtue of agape conjoined to faith)? As I have just shown in the passages cited, the evidence in the text points to the former. Recall that he says:
Love unites us to God. Love covers a multitude of sins. Love bears all things, is long-suffering in all things. There is nothing base, nothing arrogant in love. Love admits of no schisms: love gives rise to no seditions: love does all things in harmony. By love have all the elect of God been made perfect; without love nothing is well-pleasing to God. (ch. 49)
If our faith were not informed by the virtue of agape, then it would follow (given what St. Clement says here) that such faith would not unite us to God and would not be pleasing to God. Only a faith informed by the virtue of agape unites us to God and is pleasing to God, and so therefore, we have good reason to believe that for St. Clement, “the faith through which Almighty God has justified all men since the beginning of time” is faith informed by the virtue of agape.
Sola Symbolica - The 6th Sola of Protestantism 