WCF 13: Of Sanctification

The purpose of your life is to be holy as God is holy. God is “majestic in holiness” (Ex. 15:11). His holiness—his complete lack of character flaws—is the theme of angelic praise (Isa. 6:3). And God aims to manifest his holiness among his people (Ez. 28:22). This will surely happen. Those whom God justified by a declaration of righteousness, he will one day glorify by perfecting in them actual righteousness (Rom. 8:30).

But believers must begin to reflect God’s perfection now. The entire Christian journey from justification and glorification is called sanctification. In this process God renews us after his image and enables us more and more to die to sin and live righteously.[i] “Holiness … is the purpose of our justification.”[ii] God delivers his people from the hand of the enemy that they “might serve him without fear, in holiness and righteousness” (Luke 1:74–75). Hymn-writer Augustus Toplady gets to the point: “We are redeemed from sin and shame, and called to holiness.”

We need to see God’s interest in our sanctification because the devil opposes it, the world mocks it, and our own flesh resists it.. But without holiness no one will see the Lord (Heb. 12:14). So it must be our chief concern.

The Reality of Holiness

Sanctification is a fact for believers. It is a necessary consequence of regeneration or the new birth. Conversion doesn’t make a person holy, but it does begin in the believer the process of sanctification which will result in unblemished perfection by virtue of our union with Christ (Eph. 5:25-27).

Like every movement of salvation, sanctification is an application of the power of Christ’s death and resurrection. Apart from Christ sin and death dominate the human experience. Sinners are enslaved to sin and cannot free themselves (Rom. 6:16–17). But the gift of new life in Christ enables the believer to actually begin to live like Christ. Here’s how Paul explained it: “Our old self was crucified with him in order that the body of sin might be brought to nothing, so that we would no longer be enslaved to sin” (Rom. 6:6). Believers have truly “died to sin” (Rom. 6:1). Likewise, united to Christ we “have been brought from death to life” (13). Christ’s death defeated the reign of sin in God’s children; his resurrection empowers us to live again in righteousness.

So in the new birth believers awake to a new life, “having a new heart, and a new spirit created in them.” Believers have both new, upright desires, and the drive and energy to carry them out. Before conversion our hearts are inclined to evil (Gen. 6:5). After conversion everything changes: “We have the mind of Christ” () and “the strength that God supplies” to live out our new interests (1 Peter 4:11).

Christ’s death and resurrection change us through the means of God’s word and Spirit. God’s word is our food. It can energize us, repair our weakness, and fight against our moral diseases. The Spirit works with the word to weaken our lusts and strengthen us in every saving grace. It is no wonder that the Spirit who works Christ’s benefits in us is called “the Spirit of holiness” (Rom. 1:4), or more simply, the Holy Spirit. We must rely on God to sanctify us completely (1 Thess. 5:23).

But we are not passive observers in the process. We must also “strive for … holiness” (Heb. 12:14).

The Fight for Holiness

Perhaps surprisingly, Scripture describes sanctification as a conflict. Believers have been set free from sin’s total dominion (Rom. 6:6–7, 14). But sin doesn’t quit trying to re-enslave us. The law of sin wars against the believer’s mind (Rom. 7:23). The passions of the flesh battle against our souls (1 Peter 2:11; cf. James 4:11). We must hate sin. But we also still like it—sin offers some degree of pleasure, and comfort even though it never satisfies. The flesh and the Spirit “are opposed to each other” (Gal. 5:17). So we must “fight the good fight of faith” (1 Tim. 6:12). It is no wonder that warfare is so prevalent a theme in both testaments of Scripture!

Sanctification is a total war. The conflict is “throughout, in the whole man” since there remains “still some remnants of corruption in every part.” We have to fight to believe the right things. We are assaulted by doubts, even on Scripture’s clearest matters. We struggle to align our feelings with what we believe. Even when we truly want to do the right thing we must press on against fear and laziness so that we actually execute our intentions. When we do the right thing we have to fit against giving in to the pressure of critics. There is no resting in the fight. We can never reconcile the passions of the flesh and the desires of the Spirit. We must die more and more to sin. If we take a break from the biblical disciplines of faith, hope, and love, we are losing ground. If sanctification isn’t hard work it probably isn’t happening.

As slow and painful as the fight may be, the key is to make progress. We who live by the Spirit must “also keep in step with the Spirit” (Gal. 5:25). The Spirit must “govern our actions.”[iii] What that looks like from the perspective of the Spirit’s operation may be mysterious. But what it looks like from our side is straight-forward. We must constantly aim to order our lives according to God’s holy law. The law tells us what we are doing wrong so that we might turn from our false way and live more like Jesus. In a sense the law is already written on our hearts (Rom. 2:15) but we must also constantly meditate on God’s law (Ps. 119:97), testing ourselves by God’s perfect standard, and growing in its wisdom. And that’s what believers want. We fight sin because we don’t want to displease God, we fear a troubled conscience, and we can’t stand the thought of sliding deeper under sin’s influence.

And as we follow the Spirit’s lead we can be confident that we will win the war. We will lose many skirmishes—that’s a given in warfare. But we don’t lose heart when we seem to lose ground. The path to the highest pinnacle might sometimes lose elevation. But the overall trajectory is upward. We don’t make allowances for backsliding. But we also don’t give up when we fall. “The remaining corruption, for a time, may much prevail.” But, as Luther said, Jesus Christ “must win the battle.”

Growing in grace is both a command (2 Peter 3:18) and a promise (Jude 1:24–25). Take comfort in God’s promise to sanctify you. And heed his command to work out your own salvation in fear and trembling (Phil. 2:12–13).

William Boekestein pastors Immanuel Fellowship Church in Kalamazoo, Michigan. He has authored numerous books including, with Joel Beeke, Contending for the Faith: The Story of The Westminster Assembly.

[i] Westminster Shorter Catechism, Q/A 35.

[ii] Sproul, Truths We Confess, 299.

[iii] Calvin, Galatians, 169.


William Boekestein