Here is my attempt at writing a commentary on a few verses in Galatians. It reads like a regular biblical commentary. Please enjoy!
 But if, in our endeavor to be justified [dikaioō] in Christ, we too were found [heuriskō] to be [Gentile] sinners, is Christ then a servant of sin? Certainly not!  For if I rebuild [law] what I tore down [law], I prove myself to be a transgressor [law-breaker].  For through the law [nomos] I [egō] died to the law [nomos], so that I might live to God.  I have been crucified with Christ. It is no longer I [egō] who live, but Christ who lives in me [egō]. And the life I now live in the flesh I live by faith [pistis] in the Son of God, who loved [agapaō] me [egō] and gave himself for me [egō].  I do not nullify the grace [charis] of God, for if righteousness [dikaiosynē] were through the law [nomos], then Christ died for no purpose. (Galatians 2:17-21 ESV)
The Epistle to the Galatians is a sampling of the best of Paul’s writings in a single letter. New Testament Scholar, N.T. Wright refers to it as the “flamboyant younger sister of the more settled and reflective letter to Rome.” It contains a poignant biography of Paul, a personal plea for a purified gospel, a trinitarian shape, an argument against the Jewish legalists, and a practical message that is relevant to all Christians today. His tone is sometimes motherly and affectionate, sometimes fatherly and confrontational, but always ingenious in rhetoric. His clever word-plays, declarative statements, and paradoxes skillfully over-turn the arguments of his opponents and lead the churches of Galatia back to the true gospel, that is “not from men…but through Jesus Christ”(1:1). The book is a microcosm of Pauline theology, a taste of the law and gospel, faith and works, theology and practice, adoption, justification, freedom, identity, and union with God. He moves from the letter of the law to the spirit, the outward sign to the thing signified, the circumcision of the flesh to the circumcision of the heart, and the commonwealth of Israel to the spiritual household of the faith. All the mighty threads of Paul’s theology combine into one strand in the book of Galatians, a chord so strong so as to whip the churches of Galatia into maturity, and so gentle as to bind them up in unity of love once they’ve been shattered on the Rock of Christ.
A Brief History
The theology and substance of Paul’s letter in Galatians is rooted in a historical time, place, people-group, and cultural setting. His audience is made up of primarily Gentiles from the region of Galatia, a province of the Roman Empire. During Paul’s missionary journeys he planted churches in Antioch, Iconium, Lystra, and Derbe, which are all in the region of Galatia. It is to these churches that the letter is written. Acts 14:12 informs us that on his journey “…the unbelieving Jews stirred up the Gentiles and poisoned their minds against the brothers.” The “unbelieving Jews” who sought to destroy the faith of the Gentiles “poisoned their minds” through a false teaching. In Acts 15 he describes the nature of this false teaching, “But some men came down from Judea and were teaching the brothers, “Unless you are circumcised according to the custom of Moses, you cannot be saved.” The book of Galatians is fundamentally a refutation of this false teaching of the Jews, a response to a theological aberration, and a polemic against the insidious ideology that was poisoning the gospel for the Galatian churches. It has an urgency, as Paul probably penned this letter while abroad. It has an earnestness, as Paul desired to preserve the purity of the gospel entrusted to him among the Galatian churches. Finally, it has a deep-set conviction, as Paul wrote this with a zeal to maintain the flourishing of the souls that were being usurped by a false gospel.
Sinners & Saints [2:17]
 But if, in our endeavor to be justified [dikaioō] in Christ, we too were found [heuriskō] to be [Gentile] sinners, is Christ then a servant of sin? Certainly not!
Three clauses exist in verse 17. (1) “In our endeavor to be justified in Christ.” (2) “We were found to be sinners.” (3) “Is Christ then a servant of sin?” The first clause is the argument of Galatians, namely, what is the proper mechanism of justification? Paul argues that justification is not by the Law, but “in Christ.” The second clause is the accusation. The rejection of justification by the law, and the acceptance of justification in Christ, necessitates a movement away from the law to Christ. This movement means that Paul is equating Gentiles and Jews as equals, by rejecting the single-most identifying quality of the Jews—their Law. The third clause is the question. If they reject the law, and are found to be equal to Gentiles, who were known as sinners (see 2:15), then is Christ the servant or promoter of sin? The question makes the jump from equating the Jews with Gentiles, via the rejection of the Law, to Christ being the initiator of sin, because the Gentiles are sinners. He rejects the objection with the most emphatic negative available in the Greek, certainly not! Paul concludes that, even though they reject the Law, which is the essential identifying aspect of Judaism, and claim to be no better than Gentile sinners, Christ is not the servant of sin, rather he is the source of true justification.
Tear Down That Wall [2:18]
 For if I rebuild [law] what I tore down [law], I prove myself to be a transgressor [law-breaker].
Three primary verbs drive verse 18: “rebuild, “tore”, and “prove”. The “if” at the beginning of the first clause shows that this sentence is a two part conditional statement: “If I do [this], than I am [that].” We need to ask three questions. What is Paul rebuilding? What has Paul torn down? Why does rebuilding what Paul tore down make him a transgressor? The context of verse 16 and verse 19, which are both about the law, show that he is referring to the law. As a conditional statement, if Paul hypothetically rebuilds the law—the very law that he tore down—he will be seen as a law-breaker. The law brings guilt, not acquittal, judgement, not righteousness, for the one who cannot fulfill the whole law is a transgressor or lawbreaker. Therefore, if he re-erects the law, like the Galatian churches are being tempted to do, than Paul will be under the shadow of condemnation, and not righteousness.
I Died to the Law [2:19a]
 For through the law [nomos] I [egō] died to the law [nomos]…
Two apparent interpretations of this verse exist. The first is the figurative interpretation. Here, “died to the law” is a figure of speech, used to convey Paul’s rejection of the law. He is simply claiming to be dead to the law, like we might say that someone is “dead to us”, if we have cut off all ties of relationship to them. In other words, Paul is divorced or disunited from the law, relationally. The second interpretation is the literal interpretation. Here, “died to the law” is a spiritual reality, that occurs when Paul was put to death by the law, since it made him a transgressor, with the lawful penalty of death. So he used the death that was given to him “through” the law to die “to” the law. Here, both are feasible interpretations, especially when they are combined, because they give the sense that Paul has not only turned from the law, but that he has also been made spiritually dead through the law.
I Live to God [2:19b]
 …so that I might live to God.
As the second part of a two-part statement, Paul dies to the law—a literal and figurative death to the law—so that he might live to God. The contrasting states of being, death and life, suggest a resurrection from death to life, with the agent of the law. The law that put Paul to death, made it so that he might be capable of being brought back to life by God. As a connective statement, he now lives to God, in a qualitative manner, as one might live to a person they were once dead to, but have not been made alive to. This makes sense in both the figurative and literal sense. Paul, who has been made alive to God, did so in the same way that we might say we’ve been made alive in a restored relationship to a lost friend. Additionally, Paul has been made alive to God in the literal sense that he has been spiritually resurrected to God. The subjunctive verb “might live” suggests a present and future tense, for living to God, as the life to God, is initiated for all time in the future.
Crucified with Christ [2:20a]
 I have been crucified with Christ. It is no longer I [egō] who live, but Christ who lives in me [egō].
Paul makes use of the first-person pronoun “I” in order to place himself into Christ for the following verses. Theologically, this is called union with Christ, which is a spiritual participation in the economy and person of Christ. He uses the preposition “with” to describe this union as a mutual undertaking, as if he was crucified with Christ, at the same time. This signifies a present application of a past event, as if he went into the past to be crucified with Christ. He also uses the preposition “in” to describe his union as a present indwelling of a past event. The crucified Christ lives in him in the present, even though it happened in the past.
There are three parts to verse 20a. (1) I have been crucified with Christ. (2) It is no longer I who live. (3) Christ lives in me. After, Paul describes how he is dead to the law and alive to God, he describes how that happens. The first step is being crucified with Christ. The crucifixion is a death, which would make void the penalty of the law, for the law is for those who are living. Then, as he repeats himself, he clarifies that it is no longer “I” [egō] who lives. Finally, Christ lives in him, by indwelling within his person.
Faith in the Son of God [2:20b]
And the life I now live in the flesh I live by faith [pistis] in the Son of God, who loved [agapaō] me [egō] and gave himself for me [egō].
Several undeveloped technical terms pop up in verse 20b. The word “flesh”, since it hasn’t been fully developed, cannot yet mean a carnal desire, but rather it means the body that encapsulates the soul. The body still encumbers him, just as fleshly desires encumber, but it is the body that Paul is still dwelling in, until the finality of his salvation, when his body is resurrected. The word “faith” is the mechanism of his new life, which unites him to the template, the Son of God, like a stamp pressed into a mold to receive its impression. Faith is the tethering branch that binds the new egō to the righteous Son of God. Finally, the words “Son of God”, since the title is not fully developed here, means Jesus Christ, but later on it will be developed that participation in the sonship of Christ is the only person available to obtain the riches of God’s inheritance, which are available to first-born sons, namely the Son of God. Finally, the motivation for the Son of God to willingly be crucified on our behalf is his agape, love. As John Calvin puts it, “The love of Christ led him to unite himself to us…faith makes us partakers of every thing which it finds in Christ.”
The Purpose of Christ [2:21]
 I do not nullify the grace [charis] of God, for if righteousness [dikaiosynē] were through the law [nomos], then Christ died for no purpose.
By reverse engineering his statement, Paul returns to his initial argument, that justification is not by works of the law. He first claims that he does not nullify or reject, the grace of God. How is it that Paul avoids rejecting the grace of God, which he accuses the Galatian churches of doing? Nullifying the grace of God means making void the death of Christ. Paul claims that he is not making void the death of Christ, because he is seeking in union with Christ, his righteousness. Therefore, seeking righteousness through the law, makes void the death of Christ, because it is seeking without Christ, for that which is only found in Christ—his “righteousness”.
- Schreiner, Thomas. Exegetical Commentary on the New Testament: Galatians. Edited by Clinton Arnold. 1st ed. Vol. 9. Grand Rapids, Michigan: Zondervan, 2010.
- Longenecker, Richard N. Galatians. Vol. 41. Dallas, Tex.: Word Books, 1990.
- Calvin, Jean, and William Pringle. Commentaries on the Epistles of Paul to the Galatians and Ephesians. Grand Rapids: Eerdmans, 1948.