but as he who called you is holy, you also be holy in all your conduct, since it is written, “You shall be holy, for I am holy.” ~1 Peter 1:15,16
The Apostle Peter quotes this command given to the Israelites when God spoke with Moses and Aaron and it can be found in eleventh chapter of Leviticus. However, it is equally important for the Christian today; as the professed people of God, we should be like Him. The framework, with which we should build our lives in, should be the very character of God. He has called us into His kingdom and He has called us to be transformed into the image of His Son...
For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers. ~Romans 8:29
God's intent is to mold us and shape us so that our lives resemble the life of Jesus. As a potter molds and shapes clay, so God changes who and what we are. Those who are unholy and rebellious are conformed to the likeness of the One Who is holy and submissive to God. One of the ways by which God changes us is by knowing Him. This is not just an intellectual and general knowledge of God, but relational and experiential. The Apostle Paul understood this and prayed often for it to be realized in the lives of other believers...
I do not cease to give thanks for you, remembering you in my prayers, that the God of our Lord Jesus Christ, the Father of glory, may give you a spirit of wisdom and of revelation in the knowledge of him, ~Ephesians 1:16,17
To know God in this relational way and to be conformed to the image of His Son is the evidence that we are the subjects of His grace and mercy. Separation from the world and personal holiness indicate we are recipients of His salvation. And one day, when the King of Kings and Lord of Lords returns, we shall be like Him...
Beloved, we are God’s children now, and what we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is. ~1 John 3:2