Jesus answered them, "Most assuredly, I say to you, whoever commits sin is a slave of sin.
John 8:34
Surrounding context
8:33 They answered Him, "We are Abraham's descendants, and have never been in bondage to anyone. How can You say, "You will be made free'?"
8:34 Jesus answered them, "Most assuredly, I say to you, whoever commits sin is a slave of sin.
8:35 And a slave does not abide in the house forever, but a son abides forever.