Romans 1:17

For by His advent He Himself fulfilled all things, and does still fulfil in the Church the new covenant foretold by the law, onwards to the consummation of all things. To this effect also Paul, His apostle, says in the Epistle to the Romans, "But now, without the law, has the righteousness of God been manifested, being witnessed by the law and the prophets; for the just shall live by faith." But this fact, that the just shall live by faith, had been previously announced by the prophets.

Speaking to those called from among the nations that were once barren, being formerly destitute of this husband, who is the Word,-desolate formerly,-of the bridegroom. "Now the just shall live by faith".
And further on again he adds, "The righteousness of God is revealed from faith to faith."

Where three people are gathered together, there is a church, even if all three are laypersons. For each individual lives by his own faith.

But where three are, a church is, albeit they be laics. For each individual lives by his own faith, nor is there exception of persons with God; since it is not hearers of the law who are justified by the Lord, but doers, according to what the apostle withal says.

These things, then, being to come to pass, beloved, and the one week being divided into two parts, and the abomination of desolation being manifested then, and the two prophets and forerunners of the Lord having finished their course, and the whole world finally approaching the consummation, what remains but the coming of our Lord and Saviour Jesus Christ from heaven, for whom we have looked in hope? who shall bring the conflagration and just judgment upon all who have refused to believe on Him. For the Lord says, "And when these things begin to come to pass, then look up, and lift up your heads; for your redemption draweth nigh." "And there shall not a hair of your head perish." "For as the lightning cometh out of the east, and shineth even unto the west, so shall also the coming of the Son of man be. For wheresoever the carcase is, there will the eagles be gathered together." Now the fall took place in paradise; for Adam fell there. And He says again, "Then shall the Son of man send His angels, and they shall gather together His elect from the four winds of heaven." And David also, in announcing prophetically the judgment and coming of the Lord, says, "His going forth is from the end of the heaven, and His circuit unto the end of the heaven: and there is no one hid from the heat thereof." By the heat he means the conflagration. And Esaias speaks thus: "Come, my people, enter thou into thy chamber, (and) shut thy door: hide thyself as it were for a little moment, until the indignation of the Lord be overpast." And Paul in like manner: "For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth of God in unrighteousness."

The righteousness of God is revealed in the gospel in that no one is excluded from salvation, whether he be a Jew, a Greek or a barbarian. For the Savior says to everyone equally: “Come to me, all who labor and are heavy laden.” Concerning “through faith for faith,” we have already said that the first people were in the faith, because they believed God and Moses his servant, from which faith they have now gone over to the faith of the gospel. The quotation from Habakkuk means either that the one who lives in the law will also believe the gospel or that the one who believes the gospel will also believe the law and the prophets. For one of these does not have the fullness of life without the other.

If you are a just man and live by faith, if you truly believe in God, why do you, who are destined to be with Christ and secure in the promise of the Lord, not rejoice that you are called to Christ and be glad that you are free from the devil?

The righteousness of God is revealed in … the believer. Paul says that the revelation of righteousness is the approbation of those who do right. Thus he is able to say likewise that wrath is revealed toward those who do the opposite. The Jew has been brought from the faith of the appointed law to the faith which is through Christ and the Gentile from the faith of nature to the same faith in Jesus Christ.

In place of righteousness by works, which is neither sincere nor life-giving, Paul praised life through faith. The prophet said: “through faith for faith.” “If you had believed in Moses,” said Jesus, “you would have believed in me also.”

Paul says this because the righteousness of God is revealed in the one who believes, whether Jew or Greek. He calls it “the righteousness of God” because God freely justifies the ungodly by faith, without the works of the law, just as he says elsewhere: “That I may be found in him, not having a righteousness of my own, based on law, but that which is through faith in Christ, the righteousness from God that depends on faith.” He says that this same righteousness is revealed in the gospel when God grants faith to man, through which he may be justified.The truth and righteousness of God are revealed in this, when a man believes and confesses. The righteousness is of God because what he promised, he gave. Therefore, whoever believes that he has received what God promised through his prophets proves that God is just and is a witness of his righteousness.
“Through faith for faith.” What does this mean, except that the faith of God is in him because he promised, and the faith of man is in him because he believes the one who promises, so that through the faith of the God who promises the righteousness of God might be revealed in the faith of the man who believes? For to the believer God appears to be just, but to the unbeliever he appears to be unjust. Anyone who does not believe that God has given what he promised denies that God is truthful. This is said against the Jews, who deny that Christ is the one whom God promised.
“As it is written: ‘He who through faith is righteous shall live.’ ” Paul now moves over to the example of the prophet Habakkuk in order to declare that in the past it was revealed that a just man lives by faith and not by the law, i.e., that a man is not justified before God by the law but by faith.

It is right for you, my son, to have begun with the law and to have been confirmed in the gospel, from faith to faith, as it is written: “The just shall live by faith.”

But he who hath become just shall live, not for the present life only, but for that which is to come. And he hints not only this, but also another thing along with this, namely, the brightness and gloriousness of such a life. For since it is possible to be saved, yet not without shame (as many are saved of those, who by the royal humanity are released from punishment), that no one may suspect this upon hearing of safety, he adds also righteousness; and righteousness, not thine own, but that of God; hinting also the abundance of it and the facility. For you do not achieve it by toilings and labors, but you receive it by a gift from above, contributing one thing only from your own store, "believing." Then since his statement did not seem credible, if the adulterer and effeminate person, and robber of graves, and magician, is not only to be suddenly freed from punishment but to become just, and just too with the highest righteousness; he confirms his assertion from the Old Testament. And first with a short sentence, he lays open a vast sea of histories to one who has a capacity for seeing them. For after having said, "from faith to faith." he sends the hearer back to the dispensations of God, which took place thus in the Old Testament, which, when writing to the Hebrews, he explains with his usual great wisdom, showing that both the just and the sinners were justified in that way even then, wherefore also he made mention both of the harlot and of Abraham. But then here, after having just hinted at it (for he was running on to another and a pressing subject), he again confirms what he had said from the Prophets, bringing in Habakkuk before them, crying, and saying, that it is not in the nature of things for him who is to live, to live otherwise save by faith; for "the just," he says, "shall live by faith" (Hab. ii. 4), speaking about the life to come. For since what God giveth transcends reasoning entirely, it is but reason that we need faith. But the man that thinks meanly of it, and is contemptuous and vainglorious, will not effect anything at all. Let heretics hearken to the voice of the Spirit, for such is the nature of reasonings. They are like some labyrinth or puzzles which have no end to them anywhere, and do not let the reason stand upon the rock, and have their very origin in vanity. For being ashamed to allow of faith, and to seem ignorant of heavenly things, they involve themselves in the dust-cloud of countless reasonings. Then oh miserable and painful man, fit object for endless tears, should any one ask thee, how the heaven was made, and how the earth,-and why do I say the heaven and the earth? how thou wert thyself born, how nourished, and how thou grewest, art thou then not ashamed of thine ignorance? But if anything be said about the Only-begotten, dost thou thrust thyself through shame into a pit of destruction, thinking that it is unworthy of thee not to know everything? And yet disputatiousness is an unworthy thing, and so is ill-timed curiosity. And why do I speak of doctrines? for even from the corruption in our present life we have escaped by no other means than through the faith. Thus shone also all those aforetime, thus Abraham, thus Isaac, thus Jacob, thus too the harlot was saved, the one in the Old Testament, and likewise the one in the New. For, "by faith," he says, "the harlot Rahab perished not with them that believed not when she had received the spies." (Heb. xi. 31.) For if she had said to herself, "and how can they that are captives and exiles, and refugees, and live the life of vagabond tribes, get the better of us who have a city, and walls, and towers?" she would have destroyed both herself and them. Which also the forefathers of those who were then saved did suffer. For when, upon the sight of men great and tall, they questioned the manner of victory, they perished, without battle or array, all of them. Seest thou what a pit is that of unbelief! what a wall that of faith! For the one carried down endless thousands, the other not only saved a harlot, but made her the patroness of so numerous a people!

He who claims to be just without faith is a liar. Sermons for the Feast of the Nativity, Homily

What is now the church, prior to the appearance of what will be, lives in toils and afflictions, and in her the just live by faith.

This righteousness is the grace of the New Testament, by which the faithful are just as long as they live by faith, until by the perfection of righteousness they are brought to the face-to-face vision, as they are also brought to the immortality of the body itself, by the perfection of salvation.

The righteousness of God is not revealed to everyone but only to those with the eyes of faith. For the holy apostle teaches us that God foresaw this for us from the beginning and predicted it through the prophets, and even before the prophets, had it hidden in his secret will.Paul quoted Habakkuk for the benefit of the Jews, because he wanted to teach them not to cling to the provisions of the law but to follow the prophets. For many centuries before they had predicted that one day there would be salvation by faith alone.
Then departing from his admonition to the Jews, he accuses everyone else of having brazenly departed from the natural law which the Creator had placed in them. For when God made them, he did not allow them to live like beasts but honored them with reason and gave them the ability to know the difference between good and evil. Those who lived righteous lives before the time of Moses confirm this by their witness.

What is the overall meaning of the above? It is that our gospel is very great and truly marvelous if you pay careful attention to its power. For through faith in Christ all are saved, those whom the natural law has enlightened and those who follow the written law which was added to it. For when someone is informed about the resurrection from the dead, he learns that he too may share in this by obeying the gospel according to the design of the Savior. And this, says Paul, God had in ancient times announced through Habakkuk the prophet when he said: “The righteous shall live through faith.”