Romans 1:16-17 For I am not ashamed of the gospel of Christ: for it is the power of God unto salvation to every one that believeth; to the Jew first, and also to the Greek. For therein is the righteousness of God revealed from faith to faith: as it is written, The just shall live by faith.

It says that the gospel of Christ is the power of God unto salvation to every one that believes it. What is the gospel? It is the good news that the Lord Jesus Christ died on the cross for all of our sins, was buried, and rose again the third day (1 Cor. 15:1-4).

1 Corinthians 1:18 For the preaching of the cross is to them that perish foolishness; but unto us which are saved it is the power of God.

The preaching of the cross is the power of God to us that are saved or being saved! The passage continues in verses 23 and 24 saying that “we preach Christ crucified” and “Christ the power of God, and the wisdom of God.” The cross is a stumblingblock to the Jews and foolishness to the Greeks.

Why is the cross considered a stumblingblock to the Jews? Under the law, they were given the covenants. They were told that they needed to keep the commandments in order to be a holy nation, a kingdom of priests (Ex. 19:5,6). Under the law, salvation was by faith plus works. They needed to do good works, keep the law in faith in order to be saved. We learn from Romans 9:31,32 that Israel was trying to pursue righteousness by the works of the law. But, they (Israel) did not obtain righteousness, but the Gentiles did, because the Gentiles obtained it by faith. Israel tried to establish their own righteousness, instead of submitting to the righteousness of God (Rom. 10:3). They stumbled, as so many people still do today, by thinking they can obtain righteousness by their own works.

But, the Scriptures say that the righteousness of God (the righteousness that belongs to God) is revealed in the gospel and that is why the gospel of Christ is the power of God (not our own power) that saves all those that believe.

Romans 3:21 But now the righteousness of God without the law is manifested, being witnessed by the law and the prophets;

His righteousness is manifested to us without or apart from the law. That is something the Jews, and all of religion today, stumble over. His righteousness is offered as a free gift (Rom. 6:23). All we have to do is accept it, believe it.

Romans 3:24 Being justified freely by his grace through the redemption that is in Christ Jesus:

We are declared righteous freely or without a cause by his grace through the redemption (we are bought with a price, bought with the blood of Christ) that is in Christ Jesus. He paid the price for all of our sins. We deserve death, because we have all sinned against Him, but Christ died for us on our behalf.

Philippians 3:9 And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:

We are found in Him, not because we are righteous in and of ourselves and our own works, but instead we are found in Christ “through the faith of Christ, the righteousness which is of God by faith.” We are found in Christ, because we have obtained His righteousness by faith. The “faith of Christ” does not mean that Christ had faith in God like we have faith in God. Christ doesn’t need faith, for He is God. Instead, it is speaking of the righteousness which is of or belonging to God that we receive by faith (by believing). The word “faith” can be translated as “faithfulness.” We know Christ was faithful unto death, even the death of the cross (Phil. 2:8). He accomplished what He set out to do. The faithfulness of Christ is the source of the righteousness of God. In other words, the source of righteousness is the cross. For Christ is our righteousness (1 Cor. 1:30). We do not obtain it by keeping or doing the works of the law. We obtain righteousness (the righteousness of God) when we believe in the finished work of our Savior, the Lord Jesus Christ.

When we believe that Jesus Christ died for all of our sins, was buried (He put our sins away by the sacrifice of Himself (Heb. 9:26)), and rose again the third day, then we are made the righteousness of God in Him (2 Cor. 5:21). Christ is our Mediator (1 Tim. 2:5). We obtain righteousness from God through His Son’s work on the cross. When we put our trust in what He has done for us by believing the gospel, God the Father then imputes (counts) His righteousness to us (Rom. 4:3-5).

Titus 3:5 Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost;

Galatians 6:14 But God forbid that I should glory, save in the cross of our Lord Jesus Christ, by whom the world is crucified unto me, and I unto the world.