1 Peter 1:14-16 As obedient children, do not be conformed to the former lusts which were yours in your ignorance, but like the Holy One who called you, be holy yourselves also in all your behavior; because it its written, "You shall be holy for I am holy."
Holiness is the desire and duty of every Christian. When we follow Jesus we repent of sin and through Christ we no longer have to live in the former lusts of the flesh. As we grow in Christ, our lives begin to imitate Him, the Holy One. We should strive to be holy in all our behavior.
God's qualities in our lives makes us different and sets us apart, our focus and priorities must be His. On our own we cannot become holy, but God gives us His Holy Spirit to help us obey and overcome sin. We can call on God's power to free us from sin's grip.
"Blessed are the pure in heart: for they shall see God." Matthew 5:8