Both sides of the equation are vital. There is a glorious freedom in being the slaves of Christ, because “if the Son makes you free, you will be free indeed” (John 8:36). On the other hand, being a true follower of Christ means the end of human autonomy. And that is as it should be, because self-determination turns out to be nothing more than an illusion anyway. The only kind of liberty it offers is “free[dom] in regard to righteousness” (Romans 6:20)—and that is the very essence of bondage to sin. Its inevitable end is death and destruction. If we want true liberty from sin and all its fruits, it’s not autonomy that we need, but a different kind of bondage: complete surrender to the lordship of Christ.
. . . [It also] reminds us of our ransom from another master at an incredible price. It was not with the fabulous sums of all the royal estates we were bought, nor was it for handsome features or some prized skill we were purchased. But rather unlovely, without any merit, rebellious at heart, we were redeemed with the precious blood of the Master Himself.
Having thus been bought by Christ we are entirely His.