Romans 6:16
Do ye not know, that to whomsoever ye present yourselves servants to obey, ye are his servants to whom ye obey; if of sin unto death, or of obedience, unto righteousness?
John 8:34
Jesus answered them, Verily, verily, I say unto you, That every one who committeth sin is the slave of sin.
2 Peter 2:19
Preaching liberty to them, while they themselves are the slaves of corruption: for by whatever a man is overcome, by that also he is enslaved.
Matthew 6:24
No man can serve two masters: for he will either hate the one, and love the other; or he will adhere to the one, and disregard the other. Ye cannot serve God and mammon.
Romans 6:12-13
Let not therefore sin reign in your mortal body, that you should obey it in the passions thereof.
Romans 6:17
But thanks be to God, that though ye were the servants of sin, ye have obeyed from the heart the model of doctrine into which ye were delivered.
Romans 6:19-23
I speak humanly, because of the infirmity of your flesh: for as ye have presented your members servants to impurity and iniquity for iniquity; so now present your members servants to righteousness for holiness.