Paul’s terse greetings to the churches of Galatia have a reason.
“May God send us men who are not deceived, men who will respond to the forces of unbelief and compromise…. The Epistle to the Galatians is a polemic, a fighting Epistle from beginning to end. What a fire it kindled at the time of the Reformation! May it kindle another fire in our day—not a fire that will destroy any fine or noble or Christian thing, but a fire of Christian love in hearts grown cold!” (J. Gresham Machen, Machen’s Notes on Galatians, p. 8).
“[T]he new creation is that of Christ’s resurrection. For this reason the death of Christ is a turning point in the mode of existence of the old aeon. . . . Not only does Christ’s life in the flesh come to an end, but an all-important and all-embracing Transition takes place, namely, from the existence of the old to that of the new, from the old aeon to the new creation. By dying Christ has snatched his people away from the present aeon (Gal. 1:4).” (Herman Ridderbos, Paul: An Outline of His Theology, p. 66).
Quotes from the Reflection for Trinity Presbyterian Church, OPC.