but as He who called you is holy, you also be holy in your conduct, since it is written, “You shall be holy for I am holy.” 1st Peter 1:15-16
When I first read God's command 'Be holy for I am holy' I thought 'That's totally impossible!' It wasn't until I happened to come across the book The Pursuit of Holiness, by the author Jerry Bridges, that the explanation to be holy because God is holy became clear. He knows we can't be holy just like He is-that is impossible. But He calls us to a life of holy living by obeying His precepts and holy directions for our lives in our daily activities. That is completely doable.
After reading this book I became aware of how ignorant the average believer was concerning God's attribute of holiness. Shortly after reading the book I taught a weekend class on holiness. My first question to the class was; “Does God want to be known first for His holiness or His love?” To a person everyone said “For His love” and gasped when I said “He wants to be known first for His holiness.”
While we cannot attain the kind of perfect holiness that is the premier attribute of God the Father we can choose to seek to walk in a God-honoring fellowship with Him with the help of Jesus Christ and the Holy Spirit. Holiness is not an option, something you can take or leave. God's words in the Old Testament (Leviticus 11:44, 19:2, 20:7, 20:26) and the New Testament (cf 1:13-16,) are clear commands to practice and live a holy life.
Living a life of purity and righteousness, a holy life, is one of the most liberating things we can experience. It sets us apart to God, clears the conscience, allows the Holy Spirit to empower our hearts and minds, creates clearness of thought, excites the spirit within us to share Christ and disciple other Christians and leads us into a deeper fellowship with God which He, Himself, deeply desires. He is Wholly Holy in a way that is unfathomable, yet He desires us to live lives of righteousness in our behavior and our daily conduct. God says “Keep my statutes and do them; I am the Lord who sanctifies you” (Leviticus 20:8). God's holiness is defined by an incomprehensible purity. His holiness is something that is impossible for us to attain but we can still walk obediently in His holy statutes and in that sense we can be pleasingly wholly holy to Him.