Romans 6:16
Do you not know that when you habitually offer yourselves to anyone for obedience to him, you are slaves to that one whom you are in the habit of obeying, whether it is the slavery to sin whose end is death or to obedience whose end is right-doing?
John 8:34
Jesus answered them, "I most solemnly say to you, everyone who lives in sin is a slave of sin.
2 Peter 2:19
promising them freedom, though they are slaves of destruction themselves; for a man is the slave of anything that conquers him.
Matthew 6:24
No one can be a slave to two masters, for either he will hate one and love the other, or else he will be devoted to one and despise the other. You cannot be slaves of God and money.
Romans 6:12-13
Accordingly, sin must not continue to reign over your mortal bodies, so as to make you continue to obey their evil desires,
Romans 6:17
But, thank God, that though you once were slaves of sin, you became obedient from your hearts to that form of teaching in which you have been instructed,
Romans 6:19-23
I am speaking in familiar human terms because of the frailty of your nature. For just as you formerly offered the parts of your bodies in slavery to impurity and to ever increasing lawlessness, so now you must once for all offer them in slavery to right-doing, which leads to consecration.