As a Christian, you are someone who has been forgiven and are indwelt by the Holy Spirit.  God’s purpose for your life involves you progressing in your faith to maturity.  The word that the Bible uses for growth and maturity in the Christian life is the word ‘sanctification’ which describes the work of God in conforming the believer to the image of His Son.  To be ‘sanctified’ is to be set apart.  God has made sufficient provision for our sanctification in the gospel.  His ultimate goal is the development of ‘family likeness’ whereby we become conformed to the image of Christ, expressing the character traits of our heavenly Father.  This is something we can only do as the Holy Spirit works in our lives as believers.  Holiness is an imperative, but it is first an indicative.  The command to be holy is rooted in God’s gracious work.  What He commands us to do, He also provides the means.