With good will doing service, as to the Lord, and not to men. Some join the last words of the preceding verse to this clause, "from the heart with good will," etc., on the ground that it is not needed for Ephesians 6:6, for if you do the will of God at all, you must do it from the heart.
But one may do the will of God in a sense outwardly and formally, therefore the clause is not superfluous in Ephesians 6:6, whereas, if one does service with good will, one surely does it from the heart, so that the clause would be more superfluous here.
Jesus is the Overlord of every earthly lord, and his follower has but to substitute him by faith for his earthly master to enable him to do service with good will.