As Peter makes clear in his letter, salvation has already occurred and is only possible through faith in Christ and God's grace. In spite of the fact that we will not be able to conduct ourselves perfectly sinless, it is now imperative for us to live like God's people. We should strive to meet God's standard for ourselves while also understanding that we will make mistakes along the way.
Whenever we indulge in our old sinful nature and pander to the lust of the flesh, the temptations of the world, and the accusation of the devil, the Holy Spirit is powerless to sanctify our new nature in Christ. In God's eyes, even good things done in the flesh are unholy when we have the old sinful nature at work in us.
However, when we submit to the Holy Spirit's leading and guidance and allow Him to govern our new life in Christ, we are putting to death those ungodly urges. In other words, it means that we remain nailed to the Cross in our old sinful nature. By allowing the Holy Spirit to work in us, we will grow in grace and become more and more conformed to Christ's image.

Dear Heavenly Father, in the same way as You are holy, I desire to be holy as well. Sometimes, when I live in the domain of my old sinful nature, Your Spirit is quenched and grieved. My prayer is that You will help me to put to death the lusts of my flesh so that I may live a life that pleases You. Throughout my life, may I strive to be holy and set apart for Your good, and may I live to Your praise and glory.
In Jesus's name I pray. Amen.