Rom 8:12 Therefore, brethren, we are debtors—not to the flesh, to live according to the flesh
The life of a Christian is a life owned, governed and led by Christ. Not only is Christ our Savior, He is also the Sovereign Lord over us. No longer are we slaves to sin to obey it’s lusts, we are now slaves to righteousness. We are indeed debtors but not to the flesh. We owe it all to Jesus with a life of gratitude for what He has done and not a repayment.
Once we were sold under sin (Rom 7:14); but now that we have been set free from that hard task master, we have become servants to righteousness (Rom 6:22). We now have the opportunity to enjoy such glorious privileges in Christ when we mind the things of God. Nothing is owed to the flesh, we disown its unrighteous claims and are deaf to its superior demands.
As the truth is revealed, we are quick to realize how we are unable to live out what is required of us. We cannot in our own strength mortify, that is, put an end the deeds of the body. It is accomplished by the aid of the Spirit, helping our spirit in the effort.