Here are two short—but brilliant—verses to start your week with.
For we know that our old self was crucified with [Christ] so that the body ruled by sin might be done away with, that we should no longer be slaves to sin— because anyone who has died has been set free from sin. Romans 6:6-7
The “old self” and the “body ruled by sin” are not the same thing. The first is the pre-Christian “me”. And so Paul is saying that that person is dead. They died when Jesus died. There is now a completely new “me”. But the body ruled by sin still exists, because that is sin expressing itself through our bodies.
So while sin remains in us with a lot of strength, it no longer controls our personalities and lives. That person who could do nothing other than sin has died, and “has been set free from sin”. So while we still have bodies which sin, sinful behaviour goes against our deepest self-understanding, against our identity.
Imagine a wicked military force had complete control of a country, and a good army invaded and took power and threw the wicked army out of the capital and seat of government. The wicked force was out of power, defeated, but still able to create havoc in the rest of the country, as a guerrilla force. So with the Christian—sin has been thrown out of power, and has no hold over us, yet it still fights hard.