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, Gal 1:12). For the proof of which he acquaints them, 1. What his former conversation was (Gal 1:13, Gal 1:14). 2. How he was converted, and called to the apostleship (Gal 1:15, Gal 1:16). 3. How he behaved himself afterwards (Gal 1:16 to the end).