1 Peter 4:2

1 Peter 4:2. That he no longer should live the rest of his time in the flesh to the lusts of men, but to the will of God.

The doctrine of substitution is the strongest possible argument for holiness. You lived in sin once, but Christ died for your sin, so you must reckon that, in him, you died to sin, seeing that he died in your stead. And the argument is that, henceforth, your life is to be a life in him, a life of holiness, to the praise and glory of God.