In these articles, we’ve been going through an old list of questions and answers contained in the Westminster Larger Catechism, published in the 17th Century. Recently, we’ve been looking at the mediation Christ makes for his church and what that entails. We saw that part of Christ’s mediation involves the justification and adoption of God’s people. Now I want to look at another benefit brought about by Christ’s mediation: sanctification.

Sanctification is the act of being made holy. And holiness is usually associated with moral purity. If you are holy, you are set apart as clean.

But how does sanctification/holiness come to Christ’s church? The Bible teaches us that sanctification is a work of God’s grace, where God chooses to make his people holy. Paul says: ‘For he chose us in him before the creation of the world to be holy and blameless in his sight’ (Ephesians 1:4).

When did God choose who was going to be made holy? Before the creation of the world. Which means God chose who was going to be holy before anyone ever existed. Thus, his choice was purely dependent upon his grace.

Paul repeats this idea in his letter to Timothy: ‘So do not be ashamed of the testimony about our Lord or of me his prisoner. Rather, join with me in suffering for the gospel, by the power of God. He has saved us and called us to a holy life– not because of anything we have done but because of his own purpose and grace. This grace was given us in Christ Jesus before the beginning of time, but it has now been revealed through the appearing of our Savior, Christ Jesus, who has destroyed death and has brought life and immortality to light through the gospel’ (2 Timothy 1:8-10).

But who makes God’s people holy? The Bible teaches us that sanctification is done by the powerful operation of God’s Holy Spirit. Paul wrote to the church in Corinth: ‘Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God. And that is what some of you were. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God’ (1 Corinthians 6:9-11).

Similarly, in his letter to the church in Thessalonica, Paul tells us that it is the Holy Spirit that sanctifies God’s church: ‘But we ought always to thank God for you, brothers loved by the Lord, because from the beginning God chose you to be saved through the sanctifying work of the Spirit and through belief in the truth’ (2 Thessalonians 2:13).

So sanctification is the work of God’s grace where his people, who he chose before the foundation of the world, are made holy by the powerful operation of his Spirit.

But how can you make sure you are sanctified? Repent of your sins and believe that Christ died for you. If you do that, it demonstrates that you have begun to be sanctified by the Holy Spirit.