Romans 6:16
Know you not, that to whom you present yourselves as servants to obey, his servants you are whom you obey, whether of sin that leads to death, or of obedience that leads to righteousness?
John 8:34
Jesus answered them: Verily, verily I say to you, whoever works sin is the servant of sin.
2 Peter 2:19
While they promise them freedom, they themselves are the servants of corruption: for by whatever any man is overcome, he is also enslaved.
Matthew 6:24
No one can serve two masters: for he will either hate the one and love the other; or he will hold to the one, and neglect the other. You can not serve God and riches.
Romans 6:12-13
Therefore, let not sin reign in your mortal body so that you obey it;
Romans 6:17
But thanks be to God, that though you were the servants of sin, yet you have obeyed from the heart the form of teaching, in which you have been instructed;
Romans 6:19-23
I speak of what is common among men, oil account of the weakness of your flesh: for as you have presented your members as servants to uncleanness, and to lawlessness, in order to lawlessness, so now present your members as servants to righteousness, in order to holiness.