Sanctification is one of those words we run across in the Bible that we think we know its meaning but are not sure. It means to set apart or separate. "To the church of God which is at Corinth, to those who are sanctified in Christ Jesus, called to be saints, with all who in every place call on the name of Jesus Christ our Lord, both theirs and ours" (1 Corinthians 1:2).
We shy away from thinking of ourselves, much less calling ourselves, saints, yet, that is exactly what a saved person is and must be. Having been forgiven of our sins by obeying the gospel (faith, repentance and baptism), we are sanctified. We are then to live a sanctified life; a life set apart, distinct from worldly values and habits. "Therefore if anyone cleanses himself from the latter, he will be a vessel for honor, sanctified and useful for the Master, prepared for every good work" (2 Timothy 2:21).
Sanctification (sometimes translated holiness) must be the Christian's continual pursuit. "Pursue peace with all men, and the sanctification without which no one will see the Lord" (Hebrews 12:14, NASB).