Forasmuch then as Christ hath suffered for us in the flesh, arm yourselves likewise with the same mind: for he that hath suffered in the flesh hath ceased from sin; 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. (1 Peter 4:1-2 KJV)
I am to have the mind of Christ so that I will be sanctified and live according to the will of God and not the will of the flesh.
Some would read this and say that we can reach sinless perfection in this life. No, we know from other scriptures that the Bible does not teach sinless perfection in this life. Why would the Apostle Paul lament that the things he should do he doesn't do and the things he shouldn't do he does?
For the good that I would I do not: but the evil which I would not, that I do. -Romans 7:19
Now if I do that I would not, it is no more I that do it, but sin that dwelleth in me. -Romans 7:20
O wretched man that I am! who shall deliver me from the body of this death? -Romans 7:24
I believe what Peter is saying here is that when we suffer in the flesh for sin committed, we learn a lesson and we cease from committing that sin again, or at least we try harder to avoid it the next time. Our desire is to do the will of God and so we cease from willful sin and learn from sin we commit unwillfully so that we can cease from doing that thing again.