Why is sanctification in Christ important for Christians?

Sanctification is a key aspect of the believer's life, as it represents being made holy before God. According to Hebrews 10:10, we are sanctified through the offering of the body of Jesus Christ once for all. This means that Christ's work not only justifies us but sets us apart for God's holy purposes. Unlike man's efforts at sanctification, which often aim to elevate oneself, Christ's sanctification reflects His intrinsic purity and His willingness to make us pure. As we are united with Him, we share in His sanctifying work, illustrating our identity as part of His body and enabling us to live for Him.