Romans 6:16
Surely you know that, when you offer yourselves as servants, to obey any one, you are the servants of the person whom you obey, whether the service be that of Sin which leads to Death, or that of Duty which leads to Righteousness.
John 8:34
"In truth I tell you," replied Jesus, "every one who sins is a slave to sin.
2 Peter 2:19
They promise them freedom, while they themselves are slaves to corrupt habits; for a man is the slave of anything to which he gives way.
Matthew 6:24
No one can serve two masters, for either he will hate one and love the other, or else he will attach himself to one and despise the other. You cannot serve both God and Money.
Romans 6:12-13
Therefore do not let Sin reign in your mortal bodies and compel you to obey its cravings.
Romans 6:17
God be thanked that, though you were once servants of Sin, yet you learned to give hearty obedience to that form of doctrine under which you were placed.
Romans 6:19-23
I can but speak as men do because of the weakness of your earthly nature. Once you offered every part of your bodies to the service of impurity, and of wickedness, which leads to further wickedness. Now, in the same way, offer them to the service of Righteousness, which leads to holiness.