“Therefore, brothers, we have an obligation—but it is not to the sinful nature, to live according to it. For if you live according to the sinful nature, you will die; but if by the Spirit you put to death the misdeeds of the body, you will live.” Romans 8:12-13
Dietrich Bonhoeffer stated, "Grace is free; but it is not cheap." Paul reminds us that the assurance of resurrection by the indwelling Spirit places us under obligation. That obligation is not to the sinful nature and to live according to its demands; it no longer has any claim on us. Rather, we are to “put to death the misdeeds of the body.”
The lower nature does not automatically fade away when a person comes to Christ. Putting to death the evil practices of the body is an ongoing process. Freedom from our old nature only comes as we constantly rely on the active presence of the Spirit.
We must continually allow the Spirit to work in us with his instruction, exhortation, and discipline. By doing so, He will renew our lives, and at the same time,put to death our old sinful nature. Holiness is not only the standard and goal of Christians; it is also our divine calling.