Romans 6:16
Don't you know that when you offer yourselves to someone as obedient slaves, you are slaves of the one you obey either of sin, which leads to death, or of obedience, which leads to righteousness?
John 8:34
Jesus answered them, "Truly, I tell all of you emphatically, that everyone who commits sin is a slave of sin.
2 Peter 2:19
Promising them freedom, they themselves are slaves to depravity, for a person is a slave to whatever conquers him.
Matthew 6:24
"No one can serve two masters, because either he will hate one and love the other, or be loyal to one and despise the other. You cannot serve God and riches!"
Joshua 24:15
If you think it's the wrong thing for you to serve the LORD, then choose for yourselves today whom you will serve the gods whom your ancestors served on the other side of the Euphrates River, or the gods of the Amorites in whose territories you are living. But as for me and my household, we will serve the LORD."
Romans 6:12-13
Therefore, do not let sin rule your mortal bodies so that you obey their desires.
Romans 6:17
But thank God that, though you were once slaves of sin, you became obedient from your hearts to that form of teaching with which you were entrusted!
Romans 6:19-23
I am speaking in simple terms because of the frailty of your human nature. Just as you once offered the parts of your body as slaves to impurity and to greater and greater disobedience, so now, in the same way, you must offer the parts of your body as slaves to righteousness that leads to sanctification.