Romans 6:16
Do you not know that if you yield yourselves to any one to obey as slaves, you are slaves of the one whom you obey, whether of sin, which leads to death, or of obedience, which leads to righteousness?
John 8:34
Jesus answered them, "Truly, truly, I say to you, everyone who commits sin is a slave of sin.
2 Peter 2:19
They promise them freedom, while they themselves are slaves of corruption; for whatever overcomes a man, to that he is enslaved.
Matthew 6:24
No one can serve two masters; for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and mammon.
Romans 6:12-13
Therefore do not let sin reign in your mortal body, that you obey its passions.
Romans 6:17
But thanks be to God, that you who were once slaves of sin have become obedient from the heart to the standard of teaching to which you were committed,
Romans 6:19-23
I am speaking in human terms, because of the weakness of your flesh. For just as you once yielded your members to impurity and to greater and greater iniquity, so now yield your members to righteousness for holiness.