Jamieson, Fausset and Brown on Galatians 1:10

10. For--accounting for the strong language he has just used.

do I now--resuming the "now" of Ga 1:9. "Am I now persuading men?" [Alford], that is, conciliating. Is what I have just now said a sample of men-pleasing, of which I am accused? His adversaries accused him of being an interested flatterer of men, "becoming all things to all men," to make a party for himself, and so observing the law among the Jews (for instance, circumcising Timothy), yet persuading the Gentiles to renounce it (Ga 5:11) (in order to flatter those, really keeping them in a subordinate state, not admitted to the full privileges which the circumcised alone enjoyed). Neander explains the "now" thus: Once, when a Pharisee, I was actuated only by a regard to human authority and to please men (Lu 16:15; Joh 5:44), but NOW I teach as responsible to God alone (1Co 4:3).

or God?--Regard is to be had to God alone.

for if I yet pleased men--The oldest manuscripts omit "for." "If I were still pleasing men," &c. (Lu 6:26; Joh 15:19; 1Th 2:4; Jas 4:4; 1Jo 4:5). On "yet," compare Ga 5:11.

servant of Christ--and so pleasing Him in all things (Tit 2:9; Col 3:22).