Sanctification

Holy, and becoming holy

To be holy is first to be set apart for God and to belong to him. When Paul tells the Thessalonians that God's will is their holiness, his word is hagiasmos (ἁγιασμός), which older English Bibles render ‘sanctification’. Scripture speaks of sanctification in two tenses. Believers already are sanctified: Paul reminds the Corinthians, whose failings fill his letter, "you were washed, you were sanctified, you were justified" (1 Corinthians 6:11), and Hebrews says Christ "has made perfect for all time those who are being sanctified" (Hebrews 10:14). Yet holiness is also a lifelong calling: "Pursue peace with everyone, as well as holiness, without which no one will see the Lord" (Hebrews 12:14).

And we, who with unveiled faces all reflect the glory of the Lord, are being transformed into His image with intensifying glory, which comes from the Lord, who is the Spirit.

2 Corinthians 3:18

The Spirit does this work, but believers are not idle: "continue to work out your salvation with fear and trembling. For it is God who works in you to will and to act" (Philippians 2:12-13). Its root is union with Christ. Buried with him through baptism, we are raised so that "we too may walk in newness of life" (Romans 6:4). Jesus prayed, "Sanctify them by the truth; Your word is truth" (John 17:17), and the church has always looked for growth in holiness through the means God gives: the word, prayer, the sacraments and the fellowship of believers.

Sanctification and justification belong together but are not the same. Justification is God's once-for-all verdict on our standing; sanctification is the lifelong renewal of the person. Matthew Henry put it simply: "Our justification is owing to the suffering and merit of Christ; our sanctification to the working of the Holy Spirit; but both go together" Matthew Henry. Holiness is the fruit of being accepted, not the price of it, and its goal is glorification, when God's people are fully "conformed to the image of His Son" (Romans 8:29).

The church's confession

The Westminster Shorter Catechism gives the classic Protestant definition:

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.

Westminster Shorter Catechism, Q. 35

The Westminster Confession adds that this work is "throughout in the whole man, yet imperfect in this life" Westminster Confession 13.2: remaining corruption wars against the Spirit, but the Spirit of Christ keeps supplying strength, and the saints grow in grace.

How far in this life?

Every tradition receives holiness as God's will for his people, and every tradition also hears John: "If we say we have no sin, we deceive ourselves" (1 John 1:8). They differ over how far sanctification reaches before death. Reformed and Presbyterian churches, as above, teach steady but incomplete growth. Lutherans treasure Luther's teaching that the Christian is at once righteous and a sinner Luther, Lectures on Galatians, and describe the Christian life as a daily return, in repentance, to the promise of baptism Luther, Small Catechism.

The Wesleyan tradition hopes for more. John Wesley taught that God can so fill the heart with love for God and neighbour in this life that love rules it; he called this entire sanctification or Christian perfection, a gift received by faith and not a freedom from mistakes or weakness Wesley, A Plain Account of Christian Perfection. Wesleyans point to Paul's prayer: "may the God of peace Himself sanctify you completely" (1 Thessalonians 5:23).

The Catholic Church does not set sanctification beside justification as a second thing: justification itself, the Council of Trent taught, is the renewal of the inward person, and the justified, cooperating with grace, grow in that righteousness Council of Trent, Decree on Justification. The Orthodox churches describe the same path as theosis, being drawn into the life of God, and point to the promise that we "may become partakers of the divine nature" (2 Peter 1:4). For more, see the lesson Holiness and perseverance and What is sanctification?