Ephesians 6:8

Knowing that whatsoever good thing - Whatever a man does that is right, for that he shall be appropriately rewarded. No matter what his rank in life, if he discharges his duty to God and man, he will be accepted. A man in a state of servitude may so live as to honor God; and, so living, he should not be greatly solicitous about his condition. A master may fail to render suitable recompense to a slave. But, if the servant is faithful to God, he will recompense him in the future world. It is in this way that religion would make the evils of life tolerable, by teaching those who are oppressed to hear their trials in a patient spirit, and to look forward to the future world of reward. Religion does not approve of slavery. It is the friend of human rights. If it had full influence on earth, it would restore every man to freedom, and impart to each one his rights. Christianity nowhere requires its friends to make or to own a slave. No one under the proper influence of religion ever yet made a man a slave; there is no one under its proper influence who would not desire that all should be free; and just in proportion as true religion spreads over the world, will universal freedom be its attendant. But Christianity would lighten the evils of slavery even while it exists, and would comfort those who are doomed to so hard a lot, by assuring them that there they may render acceptable service to God, and that they soon will be admitted to a world where galling servitude will be known no more. If they may not have freedom here, they may have contentment if they feel that wrong is done them by men, they may feel that right will be done them by God; if their masters do not reward them for their services here, God will; and if they may not enjoy liberty here, they will soon be received into the world of perfect freedom - heaven.