Gal. 2:15, 16   Gal. 2:15 "We who are Jews by nature, and not sinners of the Gentiles, 16 Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified."           

"We who are Jews by nature, and not sinners of the Gentiles:"  Paul is making a distinction between the background of the Jews and the Gentiles at that time.  The Jews had come up under the Law of Moses.  The Gentiles had not come up under the Law of Moses.  All men are sinners.  The use of the term "sinners of the Gentiles" is not a reflection that the Gentiles were sinners and the Jews by nature were not.  Rather it is matter of knowledge based on ones background.  The Jews who had come to understand grace had a knowledge of the Law of Moses and understood that they could not be justified by the Law of Moses.            

"Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ."  No matter how hard you may try to keep the law, that same law will condemn you, as we are all breakers of the law and therefore are under the curse of the law.  Therefore, to seek to be justified by the works of the law is a great bondage and impossible to do.  As Paul said later, "by the works of the law shall no flesh be justified."  If we cannot be justified by the works of the law, then how can we be just before God?  The answer is by "the faith of Jesus Christ."  Notice, he did not say, "by faith in Jesus Christ."  The "faith of Jesus Christ" is a lot different from "faith in Jesus Christ."  The "faith of Jesus Christ" speaks of Jesus Christ's faith.  The "faith in Jesus Christ" speaks of man's faith.           

How are we justified by "the faith of Jesus Christ?"  The faith of Jesus Christ is the faithfulness of Jesus Christ to execute the covenant of redemption.  The covenant of redemption is stated for us in Rom. 8:29, 30: "For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren.  Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified."  Jesus Christ is the executor of this covenant that God made with himself before the foundation of the world.  The angel declared unto Joseph concerning the birth of Christ: "Joseph, thou son of David, fear not to take unto thee Mary thy wife: for that which is conceived in her is of the Holy Ghost.  And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins."  Jesus came to save his people from their sins.

Later Jesus said that he came to do the will of the Father (covenant of redemption): John 6:37-39 "All that the Father giveth me shall come to me; and him that cometh to me I will in no wise cast out.  For I came down from heaven, not to do mine own will, but the will of him that sent me.  And this is the Father's will which hath sent me, that of all which he hath given me I should lose nothing, but should raise it up again at the last day."  As the executor of the covenant of redemption, Jesus died to save his people from their sins and so justify them: Heb. 10:14 "For by one offering he hath perfected for ever them that are sanctified."  We read in Romans that we are justified by grace through the faithfulness of Christ and his shed blood: Rom. 3:21 "But now the righteousness of God without the law is manifested, being witnessed by the law and the prophets; 22 Even the righteousness of God which is by faith of Jesus Christ unto all and upon all them that believe: for there is no difference: 23 For all have sinned, and come short of the glory of God; 24 Being justified freely by his grace through the redemption that is in Christ Jesus:"  Therefore, being justified by the faith of Christ speaks of Christ faithfulness to execute the covenant of redemption.  It does not require man's faithfulness to believe in Christ.  Justification before God is by the grace of God alone and not by any actions of man. 

"Even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law:" The question we must ask ourselves is: "Are we justified by the faith of Christ or are we justified by the works of the law?"  Our belief is not causative of our being justified by the faith of Christ, but rather states that we have believed in Christ who has justified us by his faithfulness to execute the covenant of redemption on our behalf.  Others believe that they must keep some form of law or rule in order to be justified. 

The true gospel of the grace of Christ says that we are justified by grace through the shed blood of Christ.  The "other gospel" Paul spoke of says that we are justified by fulfilling some law or rule (the false teachers to the churches of Galatia taught them that they had to be circumcised in order to be saved).  The truth is that we are justified by the faith of Christ and not by the works of the law.

"For by the works of the law shall no flesh be justified."  This statement alone tears down all the systems of men for salvation other than the truth and that is "salvation from sin is by grace alone."  There is absolutely nothing that a man can do to justify himself before God.  Salvation from sin is God's work alone and we, the elect of God, have it by God's grace alone. 

Gal. 2:17-21  "But if, while we seek to be justified by Christ, we ourselves also are found sinners, is therefore Christ the minister of sin? God forbid. 18 For if I build again the things which I destroyed, I make myself a transgressor. 19 For I through the law am dead to the law, that I might live unto God. 20 I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me. 21 I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain."

"But if, while we seek to be justified by Christ, we ourselves also are found sinners, is therefore Christ the minister of sin? God forbid."  The "grace, but doctrine" is a great contradiction.  If we are justified by Christ alone, then it is grace.  If we are justified by the works of the law then it is works.  However, the previous verse had told us that through the works of the law shall no flesh be saved.  To try to combine salvation by grace with salvation by works leads only to confusion. 

In like manner, Paul taught concerning election: Rom. 11:5 "Even so then at this present time also there is a remnant according to the election of grace. 6 And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work."  This clearly teaches us that grace and works cannot be mixed.  If there is any work involved, then it is not grace. 

The works of the law finds us sinners as we have all sinned and come short of the glory of God.  To mix justification by Christ and justification through some work of the law is mixing grace and works.  To mix these two would make Christ the minister of sin.  To this, Paul said "God forbid."  

"For if I build again the things which I destroyed, I make myself a transgressor."  To build salvation through the law when Christ hath fulfilled the law and justified us by his blood through grace is to build again that which is destroyed.  By trying to reestablish the law is to make us transgressors of that law and is no justification at all.

"For I through the law am dead to the law, that I might live unto God."  Christ fulfilled the law to a jot and a tittle.  According to the law, he became the Lamb of sacrifice to satisfy the sins of the people.  As he died on the cross, he fulfilled the law and justified his people from their sins.  Thus, through the law and Christ sacrificial atonement under the law we are now dead to the condemning affects of the law.  We no longer are to serve the law, but to serve the one who redeemed us from the law.  Thus, we are to live unto God.

"I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me."  To be crucified with Christ cannot mean that Paul hung on a cross next to Christ, but it means that in covenant he was in Christ.  Likewise, we were in covenant in Christ as Christ was crucified.  By being in covenant in Christ, whatever Christ did, we, legally, before God were embraced by Christ's work. 

Similarly, when Christ arose, we in covenant arose with him.  We live before God, because of what Christ did for us and what he did in us.  Christ died for us and he quickened us when we were dead in trespasses and sins to give us spiritual life.  Paul is saying that the life he now lives in the flesh he has because of the faith of the Son of God.  Christ is the one who loved Paul and gave himself for Paul.  Likewise, Christ loved each of the elect and gave himself for each of the elect.  Through the faithfulness of Christ, our sin debt has been paid and we have all been quickened into spiritual life when we were before dead in trespasses and sins.  Therefore, the life that each of us now lives we live by the faith of the Son of God who loved us and gave himself for us.

"I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain."  To add anything to the grace of God is to frustrate the grace of God.  Let us be careful to not add any requirement under the false "grace, but" doctrine.  Righteousness comes by the grace of Christ.  It does not come through the works of the law.  If righteousness is by the works of the law, then Christ death was simply in vain.  God forbid that we think that Christ death was in vain.