1 Timothy 6:2

Those who are under the yoke as slaves should regard their own masters as worthy of all honor; so that the name of God and the teaching may not be blasphemed. And those who have faithful masters should not despise them because they are brothers, …

But as to servants, what can we say more than that the slave bring a good will to his master, with the fear of God, although he be impious and wicked, but yet not to yield any compliance as to his worship? And let the master love his servant, although he be his superior. Let him consider wherein they are equal, even as he is a man. And let him that 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: "not as an eye-servant, but as a lover of his master; as knowing that God will recompense to him for his subjection." 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.

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.

"And they that have believing masters, let them not despise them because they are brethren, but rather do them service, because they are faithful and beloved partakers of the benefit." As though he had said, If ye are thought worthy of so great a benefit, as to have your masters for your brethren, on this account ye ought more especially to submit. ... And why does he thus command? In the case of unbelievers, naturally, because it would have been unreasonable to address those who would pay no heed to him; but where believers were concerned, what was his reason? Because masters contribute greater benefits to their servants, than servants to their masters. For the former furnish the money to purchase for them sufficient food and clothing; and bestow much care upon them in other respects, so that the masters pay them the larger service, which is here intimated, when he says, "they are faithful and beloved, partakers of the benefit." They suffer much toil and trouble for your repose, ought they not in return to receive much honor from their servants?

"These things teach and exhort." A Teacher has need not only of authority, but of gentleness, and not only of gentleness, but of authority. And all these the blessed Paul teaches, at one time saying, "These things command and teach"; at another, "These things teach and exhort." For if physicians entreat the sick, not for the benefit of their own health, but that they may relieve their sickness, and restore their prostrate strength, much more ought we to observe this method, of entreating those whom we teach. For the blessed Paul does not refuse to be their servant: "We preach not ourselves," he says; "but Christ Jesus the Lord; and ourselves your servants for Jesus' sake"; and again, "All things are yours, whether Paul or Apollos." And in this service he serves with alacrity, for it is not slavery, but superior to freedom. For He says, "Whoever committeth sin is the servant of sin."