Though sanctification is based on what Christ accomplished in His death and resurrection and is experienced in the lives of believers by the power of the Holy Spirit, God has appointed certain means to assist believers in the pursuit of growth in grace. The believer’s progressive sanctification will be commensurate with his employment of the means of grace. The central means that God has appointed for the sanctification of His people are the Word, sacraments, and prayer.
If you were seeking a succinct definition of the biblical doctrine of sanctification, you would be hard-pressed to find a better one than that found in the Westminster Shorter Catechism. In the answer to Question 35, the Westminster divines wrote, “Sanctification is the work of God’s free grace, whereby we are renewed in the whole man after the image of God, and are enabled more and more to die unto sin, and live unto righteousness.” Although this is an accurate definition of the progressive nature of sanctification, Scripture sets out several other important aspects of sanctification that are necessary for us to gain a full-orbed understanding of this benefit of redemption. Consider the following five things:
1. Christ is the source of sanctification.
Believers are sanctified by virtue of their union with Christ. He is the singular source of sanctification insomuch as He supplies His people with all that they need to grow spiritually as they abide in Him by faith. As the Apostle Paul wrote, “You are in Christ Jesus, who became to us wisdom from God, righteousness and sanctification and redemption” (1 Cor. 1:30, emphasis added). To become the source of sanctification for His people, Jesus had to sanctify Himself in the work of redemption (John 17:19). Though He had no sin (2 Cor. 5:21), He consecrated Himself for His people by perfectly obeying the law of God as well as the mediatorial commands of God (John 10:17–18). Geerhardus Vos explained, “This . . . is not to be understood as a change in the Savior, as if this sanctification presupposes a previous lack of holiness, but as the consecration of His life in mediatorial obedience (passive and active) to God.” In addition to His obedient life, Christ was sanctified for us when He died on the cross. Since the sins of believers have been imputed to Christ, and He bore them in His body on the tree, they were judicially purged when He fell under the fiery wrath of God.
2. Regeneration is the fountain of sanctification.
Since justification is a legal benefit of redemption (i.e., a once-for-all act), sanctification more properly flows from the transformative blessing of regeneration. The implementation of a new nature (i.e., regeneration) into the lives of believers at the beginning of their Christian experience begins the process of sanctification.
