There are three key themes running throughout Paul’s letter to the Galatians: Preserving the truth of the Gospel, justification by faith alone and freedom in Christ and all three are present in this chapter. 
This chapter continues the theme of ‘the only gospel’ in chapter 1. -The question has arisen; Is Paul preaching the same gospel as the church in Jerusalem?

Paul Accepted by the Apostles
False teachers tried to undermine Paul’s message by saying that it was different to Peter’s. Paul goes to Jerusalem with Barnabas and Titus in order to set the record straight. In contemporary theology similar situations arise. There are those that try to drive a wedge between the message of Jesus and that of Paul. - We need to be alert to such divisive and misleading teaching.

v.4 ‘False brothers’ had infiltrated their ranks to spy on them. Does this happen now? Could this happen in the future? Something similar did go on in some communist countries where informants would infiltrate the churches and report back to the authorities. How did Paul respond to the false brothers? How should we?

v.4 Freedom in Christ. What is this? 
Why did some people think that Titus should be circumcised? Why did Paul oppose this?

v.9 James, Peter and John recognise the work that God is doing, through Paul, among the gentiles and offer him ‘the right hand of fellowship’. Is there a lesson to be learned here  about about working with other groups of Christians?

Paul Opposes Peter
This is one of the most tense episodes in the New Testament, - an event in which the two leading apostles where at loggerheads. Peter had been taken in by the teaching of the false brothers in Jerusalem and Paul has to set him straight. (v.14) This was particularly serious as it involved leading others astray. (v.13) How can we avoid being led astray ourselves? - We must never get complacent!

What can we learn from this situation? When should we confront other believers? How should we confront them? 

Can you think of anything in your life which effectively denies the truth of the gospel? What should you do about it?

Justified by Faith
“Justification is an instantaneous legal act of God in which he (1) thinks of our sins as forgiven and Christ’s righteousness as belonging to us , and (2) declares us to be righteous in his sight.” - Wayne Grudem

“This is the truth of the gospel. It is also the principal article of all Christian doctrine, wherein the knowledge of all godliness consisteth. Most necessary it is , therefore, that we should know this article well, teach it unto others, and beat it into their heads continually.” - Martin Luther on Justification.

Grudem’s quote tells us that there are two parts to justification. We often focus on the first. How much do we think about the second?

v.16 was one of the key verses in the Reformation. Today, as in Paul’s day there are those who argue that justification through faith in Christ alone is a dangerous doctrine as it weakens moral responsibility. -If God justifies bad people, what is the point in being good? Paul vigorously refutes this in v. 17-18. In other words he says ‘if after my justification I am still a sinner, it is my fault and not Christ’s. I have only myself to blame ; no-one can blame Christ.’
	But Paul goes further than this. When we become a christian we are justified “in Christ” (v.17), “crucified with Christ”(v.20). “Christ lives in us”(v.20). “Therefore, if anyone is in Christ, he is a new creation; the old has gone, the new has come! - 2 Corinthians 5:17 To carry on sinning as before would be incompatible with this new life.