Testifying both to the Jews, and also to the Greeks, repentance toward God, and faith toward our Lord Jesus Christ.
Ver. 21. Testifying] Not barely preaching, but vehemently pressing (as matters of greatest importance).
Repentance towards God] Not a desperate repentance (as was that of Judas), that drives men from God, but such as draws them towards him, and brings them before him, submitting to his justice, and imploring his mercy, as at the meet at Mizpeh,1 Samuel 7:5 .
Faith towards Jesus Christ] Repentance is put first, because initial repentance is a preparation to effectual faith. See Mark 1:15. See Trapp on " Mar 1:15 "