1 Timothy 6:1

But as to servants, what can we say more than that the servant should bring a good will to his master, with the fear of God, although his master be impious and wicked, but yet not yield any compliance as to his worship? And let the master love his servant, although he is his supervisor. Let him reflect on the fact that each shares equally in the other's humanity. And let one who has a believing master love him both as his master, and as of the same faith, and as a father, but still with the preservation of his authority as his master…. In like manner, let a master who has a believing servant love him as a son or as a brother, on account of their communion in the faith, but still preserving the difference of a servant.

Now I write these things unto you, not that I know there are any such persons among you; nay, indeed I hope that God will never permit any such report to reach my ears, He "who spared not His Son for the sake of His holy Church." But foreseeing the snares of the wicked one, I arm you beforehand by my admonitions, as my beloved and faithful children in Christ, furnishing you with the means of protection against the deadly disease of unruly men, by which do ye flee from the disease [referred to] by the good-will of Christ our Lord. Do ye therefore, clothing yourselves with meekness, become the imitators of His sufferings, and of His love, wherewith He loved us when He gave Himself a ransom for us, that He might cleanse us by His blood from our old ungodliness, and bestow life on us when we were almost on the point of perishing through the depravity that was in us. Let no one of you, therefore, cherish any grudge against his neighbour. For says our Lord, "Forgive, and it shall be forgiven unto you." Give no occasion to the Gentiles, lest "by means of a few foolish men the word and doctrine [of Christ.] be blasphemed." For says the prophet, as in the person of God, "Woe to him by whom my name is blasphemed among the Gentiles."

But if this be not the meaning, if he bade them forsake their masters and strive contentiously to become free, in what sense did he exhort them, saying, "Let each one remain in the calling in which he is called?" And in another place, "As many servants as are under the yoke, let them count their own masters worthy of all honor; and those that have believing masters, let them not despise them, because they are brethren who partake of the benefit." And writing to the Ephesians also and to the Colossians, he ordains and exacts the same rules. Whence it is plain that it is not this slavery which he annuls, but that which caused as it is by vice befalls free men also: and this is the worst kind of slavery, though he be a free man who is in bondage to it. For what profit had Joseph's brethren of their freedom? Were they not more servile than all slaves; both speaking lies to their father, and to the merchants using false pretences, as well as to their brother? But not such was the free man: rather every where and in all things he was true. And nothing had power to enslave him, neither chain nor bondage nor the love of his mistress nor his being in a strange land. But he abode free every where. For this is liberty in the truest sense when even in bondage it shines through.