But just as he who called you is holy, so be holy in all you do; for it is written: “Be holy, because I am holy.”
1 Peter 1:15-16 (NIV)
We want to be holy as our Father is holy.
The desire for greater holiness flows from an intimate understanding of the gospel of grace. It is the surrender of self-righteousness to fully enjoy God's imputed righteousness, which we receive through grace by faith.
As God continues to work His righteousness in us, we want to do everything that are right in His eyes. This conviction comes from the Holy Spirit, who is the Spirit of righteousness and holiness, who dwells in us. It is about being led and transformed by the Holy Spirit as we walk according to the truth of who we are and the value of what how we see ourselves in Christ.
Spirit-filled holiness is not legalistic or moralistic.
Holiness rests on your focus in Jesus. The New Covenant does not legislate holiness by rules and regulations, but it certainly calls us to do all things in Christ who empowers us to live righteously. In this sense, your holiness is determined not by what you do, but by who you believe in.
Your trust and faith in Jesus will enable you to do incredible things and live a life of holiness that are beyond the prescription of the Mosaic Law. Consider Zacchaeus's simplicity and spontaneity in repaying those he has defrauded. Or the example of the early church of sharing everything in common.
Holiness is not defined solely by “right or wrong” actions. This makes it simple to fall into legalism and hypocrisy. Rather, holiness flows from a deep intimacy and friendship with God. It is the fruit of being loved by God and wanting to love Him in return.