Romans 6:16
Know ye not, that to whom ye present yourselves servants to obey, his servants ye are whom ye obey? Whether of sin unto death, or of obedience unto righteousness?
John 8:34
Jesus answered them, Verily, verily I say unto you, he that practiseth sin, is the slave of sin:
2 Peter 2:19
While they promise them liberty, themselves are the slaves of corruption; for by whom a man is overcome, by him he is also brought into slavery.
Matthew 6:24
No man can serve two masters: for either he will hate the one and love the other, or he will cleave to the one and neglect the other.
Romans 6:12-13
Therefore let not sin reign in your mortal body, to obey it in the desires thereof.
Romans 6:17
But thanks be to God, that, whereas ye were the servants of sin, ye have now obeyed from the heart the form of doctrine into which ye have been delivered.
Romans 6:19-23
I speak as a man, because of the weakness of your flesh. As ye have presented your members servants to uncleanness and iniquity, unto iniquity, so now present your members servants of righteousness, unto holiness.