1 Corinthians 7:22
"For he that is called in the Lord, being a servant, is the Lord’s freeman: likewise also he that is called, being free, is Christ’s servant."
Cross References (ranked by relevance)
As free, and not using your liberty for a cloke of maliciousness, but as the servants of God.
Not now as a servant, but above a servant, a brother beloved, specially to me, but how much more unto thee, both in the flesh, and in the Lord?
For, brethren, ye have been called unto liberty; only use not liberty for an occasion to the flesh, but by love serve one another.
Stand fast therefore in the liberty wherewith Christ hath made us free, and be not entangled again with the yoke of bondage.
Simon Peter, a servant and an apostle of Jesus Christ, to them that have obtained like precious faith with us through the righteousness of God and our Saviour Jesus Christ:
O LORD, truly I am thy servant; I am thy servant, and the son of thine handmaid: thou hast loosed my bonds.
Jude, the servant of Jesus Christ, and brother of James, to them that are sanctified by God the Father, and preserved in Jesus Christ, and called:
Paul, a servant of Jesus Christ, called to be an apostle, separated unto the gospel of God,
Epaphras, who is one of you, a servant of Christ, saluteth you, always labouring fervently for you in prayers, that ye may stand perfect and complete in all the will of God.
For do I now persuade men, or God? or do I seek to please men? for if I yet pleased men, I should not be the servant of Christ.
For though I be free from all men, yet have I made myself servant unto all, that I might gain the more.