Galatians, the gospel and reformed theology

For our Bible reading this year Soph and I are trying to get through the reading program proposed by 'For the Love of God', although we've altered it a bit. We're only doing two chapters a day. This has meant that we are reading through Galatians the last few mornings.
A few things have struck me as I've read through this part of Scripture so I thought I'd share them with you.

1. Paul's gospel is the gospel of substitutionary atonement - that is - Christ, who was innocent and sinless took the place of a cursed sinner as he died on the cross. In this act he bore the judgment due to sinners. And since Jesus has dealt with punishment, those who were once guilty sinners can now be considered as 'righteous' and 'justified' before God.

In laymans terms - it's a straight swap - a substitution. Christ takes our place as the guilty one and takes the punishment, while we take Christ's place and are declared right with God, and now no longer fear God's wrath.
Galatians is filled with this wonderful message. In fact, throughout Galatians it seems Paul cannot separate Jesus or the Gospel from it. For example, the first thing that Paul thinks of when he mentions Jesus at the start of the letter is Jesus' sacrificial death for sin. Galatians 1:3 ...the Lord Jesus Christ, who gave himself for our sins to rescue us from the from the present evil age".
Paul understands that this justification before God comes only through faith in Christ (2:16), and that righteousness is credited to us as it was to Abraham (3:6 - ie we did not deserve it - it is credited to us).
This crediting of righteousness to our account required Jesus to be cursed on our behalf. Galatians 3:13 Christ redeemed us from the curse of the Law by becoming a curse for us, for it is written "Cursed is anyone who is hung on a tree". This is the gospel that Paul preached.

2. Paul's gospel came from God. Galatians 1:11 I want you to know brothers, that the gospel I preached is not something that man made up. I did not receive it from any man, nor was I taught it; rather I received it by revelation from Jesus Christ. Enough said.

3. Paul's gospel was the same gospel as that of the other apostles. Chapter 2 describes Paul's interaction with the apostles and notes that on meeting the other apostles James, Peter and John, those reputed to be pillars, gave me the right hand of fellowship when they recognised the grace given to me.

4. Paul declares that anyone who preaches a different gospel is cursed. Galatians 1:8
But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let him be eternally condemned! 9As we have already said, so now I say again: If anybody is preaching to you a gospel other than what you accepted, let him be eternally condemned Paul says this not just once, but twice. Those who 'pervert the gospel of Christ' or 'throw people into confusion' are on very dangerous ground.

5. Paul is not influenced by what men (no matter who they are) think. Galatians 1:10 Am I now trying to win the approval of men, or of God? Or am I trying to please men? If I were still trying to please men, I would not be a servant of Christ. In fact he says even if an angel from heaven or Paul himself are heard with anything else on their lips we are not to listen to them. No matter who it is, what position they hold or what place they occupy in the churches history - if they do not cling to Paul's gospel - that Jesus "gave himself for our sins to rescue us" - we must not side with them.