The Hebrew and Greek words for sanctify carry the idea of separation. The Hebrew word “to sanctify” (qadash) is derived from a root word that means “to cut.” We are cut out from the world in sanctification to belong to God. This is also the primary idea of the parallel New Testament word (hagiazo). Those who are being sanctified have been separated from this world, no longer joined to Adam, they have been united to Christ. The man who is sanctified is in principle lifted out of the sinful relations of life and placed in a new relation to God, Acts 20:32 Now I commit you to God and to the word of his grace, which can build you up and give you an inheritance among all those who are sanctified. We are separated from this fallen world to belong to God.


Scripture first applies the idea of holiness to God. He is distinct from all creation. For example, he exists by his own power, and thus sustains himself (John 5:26). The fact that he is distinct from all other creatures is the essence of his holiness. As creatures, therefore, we are holy only when we belong to a holy Creator. God has set us apart. This external separation symbolizes the internal separation, whereby we are consecrated in our hearts. It is of great importance to observe that this Biblical idea of holiness is never that of mere moral goodness, considered in itself, but always that of ethical goodness seen in relation to God. A man may boast of great moral improvement, and yet be an utter stranger to the work of sanctification. The Bible does not urge moral improvement pure and simple, but moral improvement with God, for God’s sake, and to the service of God.

Sanctification is that gracious and continuous operation of the Holy Spirit by which He purifies the sinner from the pollution of sin, renews his whole nature in the image of God, and enables him to perform good works.


God and not man is the author of sanctification. This does not mean, however, that man is entirely passive in the process. He can and should cooperate with God in the work of sanctification by a diligent use of the means, which God has placed at his disposal:

Since we have these promises, dear friends, let us purify ourselves from everything that contaminates body and spirit, perfecting holiness out of reverence for God (2Cor 7:1).

Work out your own salvation with fear and trembling, for it is God who works in you both to do and will according to his purpose (Phil 2:12).

Sanctification is not like justification. Justification is a legal act of God, a declaration whereby God declares us righteous because of what we have received. Whereas justification is based on imputation, sanctification is based on infusion. By way of contrast, sanctification is a work that involves the progressive renewal of God’s image in fallen man through the gracious and continuos work of the Holy Spirit. Through the operation of the Holy Spirit, the believer is purified from the pollution of sin, ethically and morally improved, renewed in true knowledge, and enabled to perform good works.

Sanctification is progressive and continuous, yet in this life it is never perfected. The process of sanctification is completed at death for the soul and at the resurrection for the body:

To the church of the firstborn, whose names are written in heaven. You have come to God, the judge of all men, to the spirits of righteous men made perfect (Heb 12:23).

Who, by the power that enables him to bring everything under his control, will transform our lowly bodies so that they will be like his glorious body (Phil 3:21).


Sanctification is a supernatural work of God. In reality it is a divine operation in the soul whereby the holy disposition imparted in regeneration is strengthened and its holy exercises increased. It is essentially a work of God, however man is expected to cooperate with the proper use of means that God gives at his disposal:

May God himself, the God of peace, sanctify you through and through. May your whole spirit, soul and body be kept blameless at the coming of our Lord Jesus Christ (1Thess 5:23).

Let me ask you only this: Did you receive the Spirit by works of the law or by hearing with faith?… Does he who supplies the Spirit to you and works miracles among you do so by works of the law, or by hearing with faith (Gal 3:2, 5).

The means that God gives is the gospel, namely the preaching of the Gospel (Rom 10:14–17).


If anyone is in Christ, he is a new creation; the old has gone, the new has come (2Cor 5:17).

Question 88. Of how many parts does the true conversion of man consist? In two parts: the dying of the old man, and the making alive of the new.

Question 89. What is the dying of the old man? Heartfelt sorrow for sin, causing us to hate and turn from it always more and more.

Question 90. What is the making alive of the new man? Heartfelt joy in God through Christ, causing us to take delight in living according to the will of God in all good works.


The negative side of sanctification consists in the removal of sin that is the pollution and corruption of the human nature. The old man, the human nature controlled by sin, has been crucified with Christ (see Rom 6:6; Col 2:11,12). In addition, there is the ongoing gradual crucifying of the flesh (c.f. Heidelberg 43, 88, 89). There is an already not yet aspect to sanctification. For we know that our old self was crucified with him so that the body of sin might be done away with, that we should no longer be slaves to sin (Rom 6:6).

Romans 6:1–14 presents a syllogism of sanctification: you have died with Christ, to be raised with Christ, to bear good fruit. In him you were also circumcised, in the putting off of the sinful nature, not with a circumcision done by the hands of men but with the circumcision done by Christ, having been buried with him in baptism and raised with him through your faith in the power of God, who raised him from the dead (Col 2:11,12). Those who belong to Christ Jesus have crucified the sinful nature with its passions and desires (Gal 5:24). Now that we have been crucified, dead, buried, and raised to newness of life, we are to put to death that old man, For if you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body, you will live (Rom 8:13).


The positive side of sanctification lies in this, that the holy disposition of the soul is strengthened, its holy exercises are increased, and thus a new course of life is provided (c.f. Heidelberg 90, 91). We were therefore buried with him through baptism into death in order that, just as Christ was raised from the dead through the glory of the Father, we too may live a new life. If we have been united with him like this in his death, we will certainly also be united with him in his resurrection (Rom 6:4–5). Therefore, if anyone is in Christ, he is a new creation; the old has gone, the new has come (2Cor 5:17). Since, then, you have been raised with Christ, set your hearts on things above, where Christ is seated at the right hand of God. Set your minds on things above, not on earthly things. For you died, and your life is now hidden with Christ in God (Col 3:1–3).


Since sanctification takes place in the heart, it naturally affects the whole man, mind, body, and soul. The change in the inner man is bound to carry with it a change in the outer life. It is completed especially in the crisis of death and in the resurrection of the dead, in which the body will be made whole. It is only when the believer becomes a participant in the death and the resurrection of Christ that they are regenerated and the work of sanctification begins. I will sprinkle clean water on you, and you will be clean; I will cleanse you from all your impurities and from all your idols. I will give you a new heart and put a new spirit in you; I will remove from you your heart of stone and give you a heart of flesh. And I will put my Spirit in you and move you to follow my decrees and be careful to keep my laws (Eze 36:25–27).