Jamieson, Fausset and Brown on 1 Peter 2:19

19. Reason for subjection even to froward masters.

thankworthy--(Lu 6:33). A course out of the common, and especially praiseworthy in the eyes of God: not as Rome interprets, earning merit, and so a work of supererogation (compare 1Pe 2:20).

for conscience toward God--literally, "consciousness of God": from a conscientious regard to God, more than to men.

endure--Greek, "patiently bear up under": as a superimposed burden [Alford].

grief--Greek, "griefs."