For if we have been united together in the likeness of His death, certainly we also shall be in the likeness of His resurrection, knowing this, that our old man was crucified with Him, that the body of sin might be done away with, that we should no longer be slaves of sin. For he who has died has been freed from sin.
This last line is the key. “For he who has died has been freed from sin.” I was born a slave to sin and grew up letting it rule over me; it was the way of life I knew. Then I accepted Jesus – accepted His death as having paid the price required to buy, from sin, the slave that I was. In Him I too died; I died to the sin that had enslaved me. Even so, though freed by death and resurrected into new life, my flesh naturally wanted to go back to being a slave because the life of slavery was familiar, an easy life where sin ordered me around and all I had to do was follow its commands.
But I am free, called to walk in newness of life. I have free will, to follow the mandates of righteousness or to return to the habit patterns of the life I lived before. With every step I must choose and yes, choosing can be challenging. The body is dead to sin, but the memories were not purged. Flesh still ponders, on occasion, that sin brought a form of pleasure – forgetting that the pleasure it brought was to the old man, the man that no longer exists.
The new man is not pleased, but rather is pained by sin. There is no joy to be found in sin; there is only sorrow. The new man is alive to and pleased by righteousness and the freedom that comes from willfully choosing to serve God. I have been freed from sin. Why, then, would I ever choose to return to its chains?