The power of sin is the law 1Cor15:56
The power in grace is knowing you have no righteousness of obeying the law. The Holy Spirit can only grow in your life, and help you fully as you accept the truth
1 John 3:7 says, “Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous.”
So does that mean John and Paul disagreed? No.
Paul was referring to the Old Law or the 613 Laws of Moses given to Israel. Paul was attacking the heresy of which I call, “Circumcision Salvationism” that was trying to invade the church. For if a person thought they had to first be circumcised in order to be saved, they would be making a Law or work (circumcision) the entrance gate and foundation of their salvation. It would be disregarding salvation by God’s grace when we first come to the Lord. It would be disregarding the foundation of grace, as well (if one were to believe in Circumcision for salvation). It would be Law Alone Salvationism (Without God’s grace).
In Acts 15, we learn that certain Jews were trying to deceive Gentile Christians into thinking they had to be circumcised to be saved and to keep the Law of Moses (the 613). The council said they gave the Gentile Christians no such commandment (See: Acts of the Apostles 15:1, Acts of the Apostles 15:5, Acts of the Apostles 15:24).
We read in Galatians 5:2, whereby Paul says if you seek to be circumcised, Christ will profit you nothing. Then in Galatians 5:4, Paul says whosoever of you are justified by the Law has fallen from grace. Obviously Paul is not referring to all forms of Law here, but the Old Law. For circumcision was a command first given to Abraham and then later to Moses, and not the church. For Paul says we are to serve in newness of spirit and not in the oldness of the letter (Romans 7:6). Paul says he is not without the Laws of God because he is under the Law(s) of Christ (See: 1 Corinthians 9:21).
Anyways, Paul is battling against those who were trying to disregard grace in exchange for going back to circumcision and the 613 Laws of Moses.
So in 1 Corinthians 15:56, when Paul says the power of sin is the Law, he is attacking the idea of those believers who were being deceived by “Circumcision Salvationism” and going back to the Old Law instead of focusing on first being saved by God’s grace and making that your foundation. Paul is not referring to all forms of Law like the laws of Christ.
In fact, Paul gives his account of his past life experience as a Pharisee who was under the Law with no grace from Jesus Christ in Romans 7:14-24. He struggled to keep the Old Law because he did not have Jesus Christ in his life yet.
But Romans 8:2 says, “For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death.”
So keeping one law makes him free from keeping another law.
The law of the Spirit of life in Christ Jesus (A New Covenant Law) has made him free from the Law of Sin and Death (The Old Covenant Law).
For the Old Law was called the law of sin and death because you could be stoned (killed) for breaking certain aspects of it.
Hebrews 7:12 says the Law has changed.
So Paul is not advocating lawlessness or disobedience because he says,
“That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit.” (Romans 8:4).
What is the righteousness of the Law [i.e. the righteous aspect or part of the Law]?
It’s loving your neighbor.
For Romans 13:8-10 says,
“Owe no man any thing, but to love one another: for he that loveth another hath fulfilled the law. For this, Thou shalt not commit adultery, Thou shalt not kill, Thou shalt not steal, Thou shalt not bear false witness, Thou shalt not covet; and if
there be any other commandment, it is briefly comprehended in this saying, namely, Thou shalt love thy neighbour as thyself. Love worketh no ill to his neighbour: therefore love
is the fulfilling of the law.”
For he that loves his neighbor fulfills the Law (i.e. the Old Law).
But this does not undo our new obligations or commands given to us in the New Covenant (after we are saved by God’s grace).
Jesus says,
“A new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another.” (John 13:34).
So we are to love the brethren in the same way Jesus loved the brethren. So we need to figure out what ways Jesus loved the brethren and do the same thing. This is a new commandment that we are to follow that is not a part of the Old law and the Jews who followed it who did not believe in being saved by God’s grace through faith in Jesus Christ.
In other words, you have to look at the whole counsel of God’s Word, and keep these things in perspective when reading Paul. If not, you are going to see a license to sin on some level (Which of course is wrong because God cannot agree with anyone justifying sin because He is holy, and good).
Grace is no more a license to sin than the existence of the tooth fairy.
For shall we continue in sin so that grace may abound? God forbid (Romans 6:1-2).