Chapter 13.1,part three

i. They, who are once effectually called, and regenerated, having a new heart, and a new spirit created in them, are further sanctified, really and personally, through the virtue of Christ's death and resurrection, by His Word and Spirit dwelling in them: the dominion of the whole body of sin is destroyed, and the several lusts thereof are more and more weakened and mortified; and they more and more quickened and strengthened in all saving graces, to the practice of true holiness, without which no man shall see the Lord. 

Sanctification is grounded in the gospel of Jesus Christ - his death and resurrection. It is produced by the Holy Spirit, who uses the Word of God to make us holy. But what effect does this have in the believer's life?  Simply put, sanctification kills and brings back to life.

The Westminster Divines believed that the sanctifying work of the Holy Spirit produces two effects in the Christian life. One is to put sin to death--what the Puritans and Presbyterians called the mortification of sin.

In order for us to make real, personal progress in holiness, the dominion of sin must be destroyed within us. The lusts which tempt us to sin must shrivel up and die. Thus sanctification involves the long slow death of sin in the life of the believer.  

At the same time, in our sanctification the Holy Spirit brings us to spiritual life--what theologians call vivification. The word "quickened" simply means to come to life. In sanctification, the Holy Spirit gradually makes us more and more alive to the grace of God.  He strengthens our commitment to personal holiness.

This is not merely a theory, but something that makes a real difference in daily life. This section of the Confession ends by speaking of the "practice of true holiness." This means keeping all of God's commandments. It means serving other people, putting them first. It means loving our family, our friends, and even our enemies. It means making a strong commitment to sexual and other forms of purity. These are the things that come to life as sin dies a long slow death over the course of a believer's life.