Before his conversion on the Damascus road (Acts 9.1-19), the apostle Paul would have found the idea of a crucified messiah abhorrent because of Deuteronomy 21.23 (‘for he that is hanged on a tree is accursed of God’). His encounter with the risen Jesus led him to build his case for justification by faith from the presupposition that Jesus’ death on the cross was a substitutionary atoning sacrifice for sin.

Paul’s contention against the false brethren or ‘judaizers’ in his letter to the Galatians is that they require Gentile converts to submit to the law and be circumcised in order to avoid persecution for the sake of the cross. John Calvin says that Paul’s mode of argumentation in Galatians is dialectical and can be reduced to four propositions:

1. Everyone is required to keep the law perfectly;

2. No one is able to keep the law perfectly;

3. All who rely on the works of the law for salvation are under a curse (Gal 3.10 ; Deut 27.26); 

4.  Christ  redeemed us from the curse of the law when he became a curse instead of us.

Paul uses ‘the curse’ as the analogy in this syllogism to demonstrate that  righteousness or justification came by faith in Christ and not from obedience to the law which can only bring a curse to sinners.

In Galatians 2 we read that Simon Peter was content to eat with uncircumcised Gentile Christians until certain Christians had arrived from James in Jerusalem who were zealous for the torah. Because of fear, Peter separated himself from the Gentile Christians, so Paul confronted him. The central issue that arose is whether it is right for Jewish Christians and Gentile Christians to enjoy table fellowship. The doctrine of justification by faith only and not by works of the law is the doctrine that provides the answer to this very important question.

Paul provides three reasons why works of the law cannot justify:

1. God has re-defined his people as those who have faith in the Messiah who fulfilled the law and obeyed it perfectly and died as the perfect sacrifice on the cross on our behalf. This is the new covenant in his blood. 

2. Works of the law will never justify because what the law does is to reveal sin and nobody can keep it perfectly.

3.  The law cannot justify, because the law imprisons everything under the power of sin and acts as a guardian for those who are immature and under the slavery of sin until the coming faith that is to be revealed in the Messiah (Gal.3.23).

The divine answer to the problem of human sin and the division between Jew and gentile lies in the covenant promise made by God to Abraham in Genesis 15.5-6 (Gal.3.6) to bless the whole world through his seed by faith, and so by the same faith that Abraham exercised, Gentiles would become the seed of Abraham (Gal. 3.29) and be united with Jews into one body through the gospel (Eph. 3.6).

Paul says that God uses the singular ‘seed’ (Gal. 3.16) to emphasize the fact that the Messiah will be one particular descendant of Abraham who would bless the world. The Messiah is the true seed of Israel who transcends Israel’s failure to keep the torah, by his faithfulness and obedience to God’s commission to die on the cross for our sins.

It is by faith in the Messiah that the promise that was made to Abraham to bless both Jews and Gentiles as one undivided family, is fulfilled. So now both Jew and Gentile find their true identity as God’s people in the Messiah by trusting in him and not by keeping the law. This faith is credited to them as righteousness just like Abraham’s faith was, and God’s promise to Abraham cannot be cancelled by the law given to Moses which came later.

So the wall of partition that Paul speaks about in Ephesians 2.19-21 between Jew and Gentile is now abolished through the Messiah. Paul explains the believer’s new life in Christ which has resulted from Christ’s death on the cross (Gal.2.20): ‘because I have been crucified with the Messiah and the Messiah now lives in me, the life I now live in the flesh, I live by the faith of the Son of God who loved me and gave himself for me’. This was not through torah; because the Messiah died to the torah, so I die to the torah. Therefore to both Jew and Gentile who believe in Jesus the Messiah, there happens a dying (‘a baptism into him’ Gal. 3.27) and a rising; a dying to the old covenant identity defined by torah which separated Gentiles and Jews and a rising into the new covenant identity defined by the Messiah himself, the faithful Israelite, whose faithfulness unto death has carried out God’s single plan of salvation to its conclusion by his death on their behalf (‘he gave himself for me’).

Peter, by separating himself from Gentiles and imposing upon them the need to be circumcised (Acts 10) or to eat kosher food (Gal.2:11-14) was in effect re-building the wall of torah that was torn down by the Messiah. 

Galatians is trinitarian. The blessing of Abraham that comes to both Jews and Gentiles through faith also brings the promise of the Spirit through faith (Gal. 3.14). The purposes of the Father are accomplished by the Son through the Spirit of the Son. God who sends the Son also sends the Spirit of the Son by whom we are adopted as God’s children and we are able to call God ‘Father’ because we are by the same Spirit united as one body of the Son (Gal.4:6-7). And because this new family of God shares the same Spirit we are able to have fellowship with God and fellowship with one another (‘faith working through love’ Gal.5.6).

If a person – a Gentile convert – goes back to the law and becomes circumcised, this person has fallen from grace and is re-introducing again the barrier that was broken down by the Messiah and is again separating Jew and Gentile by the old covenant identity of circumcision because the only basis of fellowship for both Jew and gentile is in the Holy Spirit and the hope of righteousness that results from faith (Gal. 5.2-6 ).

But if we live by the Spirit we will become expressions of the one to whom we belong, the Messiah, and we will not fulfil the desires and passions of the flesh (Gal. 5.16) but the Spirit will transform us into his image and likeness and we will exhibit in our life the fruits of a practical righteousness (Gal.5.22-23).