21 But now apart from the Law the righteousness of God has been manifested, being witnessed by the Law and the Prophets, 22 even the righteousness of God through Jesus Christ’s faithfulness for all those who believe; for there is no distinction; 23 for all have sinned and fall short of the glory of God, 24 being justified as a gift by His grace through the redemption which is in Christ Jesus; 25 whom God displayed publicly as a propitiation in His blood through faith. This was to demonstrate His righteousness, because in the forbearance of God He passed over the sins previously committed; 26 for the demonstration, I say, of His righteousness at the present time, so that He would be just and the Justifier through Jesus’ faithfulness. (Rom3:21-26)
The first point to make concerns the translation. The Greek does NOT refer to “faith in Christ” in this passage but the faith of Christ. That pertains to Jesu’s faithfulness [note 1] to His Father’s will culminating in His death on the Cross. How this relates to the Christian’s faith in Christ is clarified in the following verse in Galatians:
Having known that a man is not declared righteous by the works of the Law but through the faithfulness of Christ; we (Christians) believed in Christ Jesus that we might be declared righteous by the faithfulness of Christ and not by the works of Torah, therefore no flesh shall be declared righteous by works of the law
This translation resolves the more usual version’s triple tautology and shows how Christ’s faithfulness in terms of His saving work on humanity’s behalf benefits those who do not have a personal knowledge of it yet instinctively fear God and “attend to moral discipline” as some early Fathers refer to the matter. Countless billions who have lived have not benefitted from hearing a faithful account of Jesus’ teaching and the Good News of His Kingdom. Most Church Fathers before Augustine’s fearsome assertions recognized that man in his natural state, although unable to raise himself to eternal life had effectual free will to choose and practice what is just and in accordance with sound reason . Some of these early Church Fathers including Justyn Martyr and Origen regarded the seed of reason provided to all men equipping them with a degree of wisdom and a sense of justice as the essence of “Christ” Himself. I tend to refer to the same concept as the light of Christ reflected in the conscience. Either way it is a sufficient object of faith resulting in divine acceptance for those who defer to it (earlier post). This is not an assertion of absolute universalism for not all do .
In terms of a person’s faith in Christ as Saviour, that replaces the requirements of Torah observance previously required of those set apart as God’s royal priesthood on earth (Ex19:6 cf. 1Pet2:9). Paul’s polemics against those Jewish converts especially in the Galatian churches who said otherwise is the context of his frequent references to the fact that justification within the Covenant of Promise is by faith in Christ as opposed to “works of the Law” such as circumcision and observing dietary and sacral regulations (Gal4:9-10).
The point Paul will repeatedly make is that those privileged to be God’s people under the New Covenant are there on the basis of free grace, a gift provided through the redemptive work of Christ (v24). It is not through their own good works or virtue. However (and this is where many have disregarded the other side of the equation), such have been chosen “to perform good works that God has fore-ordained that we should walk in them” (Eph2:10). And as Paul has just stated in the previous chapter, that is the basis and condition upon which people will finally be judged and rewarded (Rom2:6-7).
More needs to be explained, for example concerning “propitiation” and what Paul meant (and didn’t mean) by “the righteousness of God” but that will come to light through future posts.
 “faith” and “faithfulness” are the same word in biblical Greek
 These are the satanic seed (children of the devil), epitomized by Cain, alluded to by Christ (Mt15:13), elucidated a little in the first epistle of John and explained in detail in chapter 6 of The Little Book of Providence [Free PDF HERE]