In this chapter, after the preface or introduction (Gal. 1:1-5), the apostle severely reproves these churches for their defection from the faith (Gal. 1:6-9), and then proves his own apostleship, which his enemies had brought them to question, I. From his end and design in preaching the gospel, Gal. 1:10. II. From his having received it by immediate revelation, Gal. 1:11, 12. For the proof of which he acquaints them, 1. What his former conversation was, Gal. 1:13, 14. 2. How he was converted, and called to the apostleship, Gal. 1:15, 16. 3. How he behaved himself afterwards, Gal. 1:16-24.