Paul support his argument that all are under the power of sin with scriptural quotes:
3:10 - Ecclesiastes 7:20; Ps 14:1–3; Ps 53:2–4;
3:13 - Ps 5:10 (LXX); 10:7 (LXX); 14:5; 140:4;
3:14 - Ps 10:7; Is 59:7–8;
3:15 - Proverb 1:16;
3:18 - Ps 36:5.
Based on these quotes, the following are the marks (signs) of general sinfulness of humanity:
What is the conclusion? shut up! (3:19), which means:
The acknowledgment of general sinfulness of humanity - both Jews and Gentiles alike - leads to Paul’s following statement in 3:20. What does it day:
After hearing about general sinfulness of humanity and no way to gain justification by human wisdom (Gentiles) or the law (Jews), Paul brings us back to the topic of God’s righteousness. The term God’s righteousness means God’s mercy. The key to our justification - freedom from the power of sin and grace to live a holy life - is God’s mercy, that merciful love that has pity on the fallen humanity seen already in the Old Testament (see Gen 3:21; 6:8).
This justification is accessible by “faith of / in Jesus Christ”. Grammatically, verse 3:22 is in genitive that calls for a translation “faith of Jesus Christ”. Moreover, the word “pistis” - faith - can also be translated as “faithfulness”. Thus, we would have “faithfulness of Jesus Christ” (see also 3:26; Gal 2:16, 20; 3:22; Eph 3:12; Phil 3:9).
The Gospels and the Letter to the Hebrews present to us Jesus as having faith/trust in His Father (Matt 26:39–46; Heb 5:7–8). This faith expressed itself in obeying the will of the Father (Heb 10:5–7 - referring to Jesus). It is the fulfillment of this will that saves us (Heb 10:10). Moreover, Hebrews also presents Jesus as “the author and perfecter of faith” (Heb 12:2).
Rendering Rom 3:22 as “faith/faithfulness of Jesus Christ” powerfully connects with the beloved phrase of Paul from the book of Habakkuk. In the version of Septuagint, the verse reads: “but the just shall live by my faith/faithfulness” (Hab 2:4; see Rom 1:17; Ga; 3:11). These words are spoken by the Lord to the prophet (Hab 2:1). Thus, the prophet had foreseen what has been realized in the New Testament: the just lives by Christ’s faithfulness.
On the other hand, if we maintain the more common translation of this verse as “faith in Jesus Christ” then “faith” should be properly understood (see Matt 7:21; Luke 6:46). It means trust expressed in obedience to Christ. Hebrew makes it clear that Jesus is the cause of eternal salvation only [obvious from the context] for all, who obey Him (Heb 5:9). After all, Paul was called to bring the Gentiles to “the obedience of faith” (Rom 1:5). Thus faith and obedience are interconnected.
“To all the believing” (3:22). The righteousness of God comes through faith of/in Jesus Christ; not through the law or any other means. The term “the believing [ones]” will be explained in chapter 4 by showing the example of Abraham. To be counted among “the believing” one needs to have faith of Abraham.
3:23. This is one among the most famous verses in the entire Scripture. When comes to the glory of God - it points to his presence among His people (see Ex 40:34; Ezekiel 1:28; 11:22–23; 43:2–5). The glory of the Lord cannot tolerate sin. Thus, human sinfulness causes it to leave.
3:24. The term redemption “apolytrosis” has commercial meaning. It means reclaiming a pawned item or mortgaged property (Lev 25:24). The term connotes an obligation upon the part of a buyer of that item or property and upon a kinsmen of the person who is pawning or mortgaging.
This understanding carries a powerful theological idea. What does it mean, when we say that God is Israel’s “Redeemer?” When Israel is in distress, unable to redeem itself, God is that kin, who has an obligation to redeem it. What does it mean when we say that Christ is our - Church’s - “Redeemer”? Christ is our closest kin - elder brother (Heb 2:12) - who came to assist us in setting us free from the predicament of sin. The ‘buyer’ in this case, the devil (Heb 2:14–15), could not refuse that act of reclaiming us from his power.
Paul makes it clear that the redemption is (1) God’s grace, (2) it justifies, (3) it is in Christ Jesus.
3:25–26. The blood of Christ is the price of our redemption (1 Cor 6:20; 7:24; 1 Peter 1:18–19).
The term “propitiation” (hilasterion in Greek) refers to the cover of the ark of the covenant (Ex 25:17–22). On this cover, the blood of the sacrificial animals was poured out by the high priest of the temple on the day of the atonement (Lev 16:15–19).
See also Gen 32:20(21) LXX - where the word “propitiate” as a verb is used in the story between Jacob and Esau. Jacob wants to propitiate Esau face with the gifts that go ahead of him. Jesus’ blood goes ahead of us to propitiate God’s face.
Thus, Jesus becomes “hilasterion” also through faith, but it is faith in His blood.
Paul further indicates that:
3:27–29. Paul makes another interesting argument. If justification would come true the law of works, then the whole world would have to become Jewish. All the Gentile nations in order to experience this justification would have to become Jews first, which means an obedience to all Jewish laws, customs, and tradition.
But, it is not necessary. God is not just a God of the Jews, but the God of all and he provides only one mode of justification for all, including the Jews - FAITH.
3:30–31. Here we find that God will justify (future tense) the Jews - circumcision - “out of / by faith”, and the Gentiles - uncircumcision “through faith”. Apparently there is no difference between “out of/ by” and “through” faith. It is worth noting, however, that here justification refers to future. Perhaps, Paul has in mind that this mode of justification will remain for the generations to come. There will not be any other mode of justification in the future, whether for the Jews or the Gentiles.
How about the law then? Useless? Here, Paul only negates the statement that the law could be seen is useless then if the only mode of justification is faith. But, from our discussion in the letter to Galatians we already know what he means by establishing the law. Later, in this letter, he will also explain the role of the law (Rom 7:7–13; 10:4, see also Matt 5:17).