Romans 1:16-17

For I am not ashamed of the gospel of Christ. For it is the power of God for salvation to everyone who believes, to the Jew first, and also to the Greek. For in it the righteousness of God is revealed from faith to faith. As it is written, “The just shall live by faith.”
Romans 1:16-17, Modern English Version (MEV)
 
No one could ever accuse Paul of being timid in the presentation of the Gospel, much less that he was ashamed of it. Paul's belief in the Gospel was absolute and unwavering, even to the point of death. On the other hand, while many of us today profess an abiding faith in the Gospel, things become a little dicey when things don't go according to plan or expectation. We are, sad to say, fair weather friends of God. When the weather begins to turn stormy, our friendship takes a beating. Oh that we could have the rock solid faith of Paul. Things would be so much different.
 
From Adam Clarke’s Commentary on the Bible we find the following detail. It is a bit long, but I think you’ll find it worthwhile:
 
I am not ashamed of the Gospel of Christ - This text is best illustrated by Isa_28:16; Isa_49:23, quoted by the apostle, Rom_10:11: For the Scripture saith, Whosoever believeth on him, shall not be ashamed; i.e. they shall neither be confounded, nor disappointed of their hope. The Jews, by not believing on Jesus Christ, by not receiving him as the promised Messiah, but trusting in others, have been disappointed, ashamed, and confounded, from that time to the present day. Their expectation is cut off; and, while rejecting Christ, and expecting another Messiah, they have continued under the displeasure of God, and are ashamed of their confidence. On the other hand, those who have believed on Christ have, in and through him, all the blessings of which the prophets spoke; every promise of God being yea and amen through him. Paul, as a Jew, believed on Christ Jesus; and in believing he had life through his name; through him he enjoyed an abundance of grace; so that, being filled with that happiness which an indwelling Christ produces, he could cheerfully say, I am not ashamed of the Gospel of Christ. And why? Because he felt it to be the power of God to the salvation of his believing soul. This appears to be the true sense of this passage, and this interpretation acquires additional strength from the consideration that St. Paul is here most evidently addressing himself to the Jews.
 
It is the power of God unto salvation - δυναμις γαρ θεου εστιν· The almighty power of God accompanies this preaching to the souls of them that believe; and the consequence is, they are saved; and what but the power of God can save a fallen, sinful soul?
 
To the Jew first - Not only the Jews have the first offer of this Gospel, but they have the greatest need of it; being so deeply fallen, and having sinned against such glorious privileges, they are much more culpable than the Gentiles, who never had the light of a Divine revelation.
 
And also to the Greek - Though the salvation of God has hitherto been apparently confined to the Jewish people, yet it shall be so no longer, for the Gospel of Christ is sent to the Gentiles as well as the Jews; God having put no difference between them; and Jesus Christ having tasted death for Every man.
 
For therein - In the Gospel of Christ.
 
Is the righteousness of God - God’s method of saving sinners.
 
Revealed from faith to faith - Shown to be by faith, and not by the works of any law; for Abraham, the father and founder of the Jewish people, was justified by faith, before even the law was given; and by believing, in reference to the spiritual object held forth in the various ordinances of the law, and now revealed under the Gospel, he and all his believing descendants have been justified. And thus the faith of the old covenant led on to the faith of the new covenant, which shows that salvation has been by faith from the call of Abraham to the present time. And, from the beginning, all that were just or righteous in the earth became such by faith, and by this principle alone they were enabled to persevere; as it is written, The just shall live by faith. That δικαιοσυνη, which we translate righteousness in this verse, signifies God’s method of saving mankind by faith in Christ, is fully evident from the use of the term in Rom_9:30: The Gentiles which followed not after Righteousness - who had no knowledge by revelation, of God’s method of justifying and saving sinners, have attained to Righteousness - have had imparted to them God’s method of salvation by faith in Christ. Rom_9:31: But Israel, the Jews, which followed after the law of righteousness - that law, the end or object of which is Christ, and through him justification to all that believe (Rom_10:4), have not attained to the law of righteousness - have not found out the genuine plan of salvation, even in that law which so strongly and generally proclaims justification by faith. And why have they not found it? Rom_9:32: Because they sought it not by faith, but as it were by the works of the law - they did not discern that even its works or prescribed religious observances were intended to lead to faith in that glorious Mediator of whom they were the types and representatives; but the Jews trusted in the observances themselves, hoping to acquire justification and final salvation by that means. For they stumbled at the stumbling-stone - at the doctrine of Christ crucified as the only sure ground on which the expectation of future salvation can be founded. Therefore, being ignorant of God’s righteousness - God’s method of saving sinners, and going about to establish their own righteousness - their own method of salvation, by the observance of those rites and ceremonies which should have led them by faith to Christ, they did not submit themselves to the righteousness of God - they would not submit to be saved in God’s way, and therefore rejected, persecuted, and crucified the Lord Jesus; see Rom_10:3. This collation of passages most evidently shows that the word righteousness here means simply God’s method of saving sinners, or God’s way of salvation, in opposition to the ways and means invented by the fancies or prejudices of men.
 
There are few words in the sacred writings which are taken in a greater variety of acceptations than the word צדקה tsedakah in Hebrew, and δικαιοσυνη in Greek, both of which we generally translate righteousness. Our English word was originally rightwiseness, from the Anglo-Saxon justice, right, and to know; and thus the righteous man was a person who was allowed to understand the claims of justice and right, and who, knowing them, acted according to their dictates. Such a man is thoroughly wise; he aims at the attainment of the best end by the use of the best means. This is a true definition of wisdom, and the righteous man is he that knows most and acts best. The Hebrew צדק tsadak, in its ideal meaning, contains the notion of a beam or scales in equipoise, what we call even balance; and it is well known that in all the personifications of Justice, both ancient and modern, she is represented as a beautiful female with a bandage on her eyes, and a beam and scales in her hand, so perfectly poised that neither end preponderates.
 
The Greek word δικαιοσυνη has been derived from διχαζω, to divide; and hence δικη, justice, because it is the property of this virtue to divide to each his due. With other etymologies it is useless to trouble the reader. Both the noun δικαιοσυνη and the verb δικαιοω have a great variety of meaning in the New Testament; but they are all reducible to this original idea, acting according to the requisitions of justice or right. It may not be improper to notice some of the chief of these acceptations in this place.
 
1. The act of distributing to each man his due is the sense of the word, Act_17:31: He will judge the world in Righteousness, i.e. according to the principles of eternal justice and rectitude. See also Rev_19:2: In Righteousness doth he judge and make war.
 
2. It signifies a holy life, as proceeding from piety towards God. Luk_1:75: Might serve him in holiness and Righteousness all the days of our life.
 
3. It signifies benignity, liberality, and particularly almsgiving, as justice and righteousness require us, being only stewards of God’s bounty, to share it with the necessitous. Mat_6:1: Take heed that ye do not your Alms, δικαιοσυνην, your Righteousness, before men. Rom_3:5: But if our unrighteousness commend the Righteousness, the benignity of God. 2Co_9:10: Increase the fruits of your Righteousness, i.e. of your liberality.
 
4. It signifies God’s method of saving sinners; the way which is agreeable to his righteousness and liberality. See the former part of this note, and the scriptures there referred to.
 
5. It signifies the reward or issue of liberality. 2Co_9:9: He hath scattered abroad; he hath given to the poor; his Righteousness - the reward of his bounty, remaineth for ever. See Psa_112:9.
6. It signifies the whole collection of graces, which constitute the complete Christian character. Mat_5:6: Blessed are they that hunger and thirst after Righteousness - they who ardently long for the full salvation of God. Mat_5:10, Mat_5:20: If your Righteousness exceed not the righteousness, etc. Mat_6:33: Seek the kingdom of God and his Righteousness.
 
7. It signifies the result of faith in God and submission to his will, exemplified in a holy and useful life. Heb_11:7: By faith Noah prepared an ark, and became heir of the Righteousness which is by faith - he escaped the deluge and became the instrument of repeopling the world.
 
8. It signifies an exact observance of religious ordinances and precepts. Php_3:6: Touching the Righteousness which is of the law, blameless - having lived in an exact conformity to all the Mosaic precepts. In this sense it is to be understood, Mat_3:15: Thus it becomes us to fulfill all Righteousness - to observe every precept of the law.
 
9. It signifies the favor or pardoning mercy of God. Rom_4:6: The blessedness of the man unto whom God imputeth Righteousness - without works - the man is happy to whom God has granted the remission of sins, without respect to his observance of the law of Moses.
 
10. In 2Co_5:21, δικαιοσυνη, righteousness, is put for δικαιος, righteous: That we might become the righteousness of God - that we might receive such a righteousness or holiness, such a salvation, as is worthy of God’s grace to impart, and such as the necessities of mankind require.
 
A few of the leading acceptations of the verb δικαιοω, which we translate to justify, may be here properly subjoined, as this verb is so repeatedly used in this epistle.
 
1. It signifies so declare or pronounce one just or righteous; or, in other words, to declare him to be what he really is. 1Ti_3:16: He was Justified in the Spirit. - By the almighty power of the Spirit he was proved to be the True Messiah.
 
2. To esteem a thing properly. Mat_11:19: Wisdom is Justified of her children. - Wisdom, propriety of conduct, is properly estimated by wise men.
 
3. It signifies to approve, praise, and commend. The publicans Justified God, Luk_7:29; praised him for calling them to such a state of salvation. Luk_16:15: Ye are they which Justify yourselves before men - Ye are self-commended, self-applauded, and self-praised. In this sense it is often used in the Greek apocryphal books. Ecclus. 7:5: Justify not thyself before the Lord - Do not applaud thyself in the presence of thy - Maker. Ecclus.10:29: Who will Justify (praise or applaud) him that sinneth against his own soul. Ecclus 18:2: The Lord only is righteous, δικαιωθησεται, shall be Justified, i.e. praised, because there is none other but he.
 
4. The verb δικαιοομαι is used to clear from all sin. 1Co_4:4: For I know nothing by myself; yet am I not hereby Justified - A man’s own consciousness of integrity is not a proof that he is clear from all sin in the sight of God.
 
5. A judge is said to justify not only when he condemns and punishes, but also when he defends the cause of the innocent. See Eurip. Heraclid. ver. 190. Thucyd. iii. p. 200. Polyb. iii. 31, and Schleusner on δικαιοω. Hence δικαιουσθαι is taken in a forensic sense, and signifies to be found or declared righteous, innocent, etc. Mat_12:37: By thy words shalt thou be Justified - thou shalt be declared to be righteous. Rom_3:4: That thou mightest be Justified in thy saying - that thou mightest be proved to be true in what thou hast said.
 
6. It signifies to set free, to escape from. Act_13:39: And by him all that believe are Justified from all things, from which ye could not be Justified by the law - by faith in Christ a man escapes those evils which, otherwise, the law of Moses would inflict upon him. Rom_6:7: For he that is dead, δεδικαιωται, is Justified, properly rendered by our translators, is Freed from sin.
 
7. It signifies also to receive one into favor, to pardon sin. Rom_8:30: Whom he called, them he also Justified - he received them into favor and pardoned their sins. Luk_18:14: This man went down to his house Justified - he humbled himself, repented of his iniquity, and God forgave his sin. Rom_3:20: By the deeds of the law there shall no flesh be Justified - no soul can have his sins forgiven through the observance of the Mosaic law.
 
Rom_4:2: If Abraham were Justified (had his sin pardoned) by works. 1Co_6:11: Such were some of you, but ye are Justified - ye are received into the Divine favor, and have your sins forgiven. See Jas_2:21-25; Rom_3:24, Rom_3:28; Rom_5:1, Rom_5:9; Gal_2:16, Gal_2:17; Gal_3:11, Gal_3:24; Gal_5:4; Tit_3:7. In all these texts the word justify is taken in the sense of remission of sins through faith in Christ Jesus; and does not mean making the person just or righteous, but treating him as if he were so, having already forgiven him his sins.
 
The just shall live by faith - This has been understood two ways:
 
1. That the just or righteous man cannot live a holy and useful life without exercising continual faith in our Lord Jesus: which is strictly true; for He only who has brought him into that state of salvation can preserve him in it; and he stands by faith.
 
2. It is contended by some able critics that the words of the original text should be pointed thus: ‘ο δε δικαιος εκ πιστεως, ζησεται. The just by faith, shall live; that is, he alone that is justified by faith shall be saved: which is also true; as it is impossible to get salvation in any other way. This last meaning is probably the true one, as the original text in Hab_2:4, speaks of those who believed the declarations of God when the Chaldeans besieged Jerusalem, and, having acted conformably to them, escaped with their lives.