Grace to you and peace from God the Father and our Lord Jesus Christ, who gave Himself for our sins, that He might deliver us from this present evil age, according to the will of our God and Father, to whom be glory forever and ever. Amen.
Galatians 1:3-5 NKJV

I love the way Paul greets the Galatians, reminding them of their faith, and what it is, or should be, in.

Then, wow he slams them with there turning away from what they first believed in.  Pow!

I marvel that you are turning away so soon from Him who called you in the grace of Christ, to a different gospel, which is not another; but there are some who trouble you and want to pervert the gospel of Christ.
Galatians 1:6-7 NKJV

Later he reminds them where there faith is, or should be, and what that means to those around them:
For you are all sons of God through faith in Christ Jesus.
For as many of you as were baptized into Christ have put on Christ.
There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus.
And if you are Christ’s, then you are Abraham’s seed, and heirs according to the promise.
Galatians 3:26-29 NKJV

He reminds us that we are all one in Christ, “baptized into Christ” means we are united as one.  The body of believers, not religions, or churches, but the body of Christ, one united with Christ through baptism to do his will.