A Christian is someone who has been renewed (regeneration), is being renewed (sanctification), and will be renewed (glorification). His sin has been dealt with judicially (justification), it is being dealt with progressively (sanctification), and it will be dealt with permanently (glorification). These nuances help us make sense of the presence of sin in the life of a Christian. While we saints remain in these bodies of sin in a fallen world, we continue to battle our own flesh and its non-reigning, extant sin—which is why Christians still do bad things. But one day, coming soon, we will do only that which is good, in glorified bodies and a renewed world that aren’t polluted by sin and corruption. 

There are generally two basic forms in which this question is asked. First, most Christians have at some point asked themselves, “If I’m a true Christian, why do I keep sinning?” Second, Christians and others have asked questions like, “How could Christians have committed such atrocities during the Crusades?” The two questions are different, but they have essentially the same theological and biblical answer. The answer requires us to understand what Scripture says is true of Christians in the threefold application of redemption. We must consider the Bible’s teaching about what has already happened to the Christian, what is happening to the Christian, and what has not yet happened to the Christian.

Already: What Has Happened to Christians (Regeneration, Justification, Adoption)

According to the Bible, when a person becomes a Christian, he has gone from death to life. He has experienced what we often call “regeneration.” This is foundational to our Christian identity. The Christian is a new creation (2 Cor. 5:17). He has been born again (John 3:3; 1 Peter 1:3). He was in darkness, and now he is in light (Acts 26:18; Eph. 5:8; 2 Cor. 6:14; 1 Peter 2:9). He was dead in trespasses and sins, and now he is alive together with Christ (Eph. 2:1–2; Col. 2:13). He was a slave to sin, and now he is a slave to righteousness (John 8:34; Rom. 6:1–23; Gal. 5:1). He had a heart of stone, and now he has a heart of flesh (Ezek. 11:19; 36:26). Regeneration and its fruit, conversion to Christ, signify a drastic change in identity. Regeneration does not, however, purge the effects of our fallenness from our souls and bodies. Regeneration imparts spiritual life into the soul, but one’s history before regeneration is not changed. This means that a Christian will hate his sin, but he still might be attracted to the same sins as he was before conversion. In the new birth (i.e., regeneration), we are effectually called, meaning that the Spirit not only calls us to embrace the Lord Jesus Christ by faith but also gives us the ability to respond to that call. When we place our faith in Christ, the Spirit unites us to Christ, from whom we receive the benefits of redemption, including “justification, adoption and sanctification, and the several benefits which in this life do either accompany or flow from them” (Westminster Shorter Catechism 32). In our union with Christ, justification, adoption, and sanctification are distinct yet inseparable benefits. In the act of justification, a person is pardoned of all sins and accepted as righteous in the sight of God only on account of the imputed righteousness of Christ received by faith alone (WSC 33). In the act of adoption, a person is received into the number and given a right to all the privileges of the sons of God (WSC 34). In the work of sanctification, a person begins to be renewed in his whole being after the image of God and is enabled more and more to die unto sin and live unto righteousness (WSC 35). Whereas justification and adoption are acts of God, sanctification is a work of God. Justification and adoption are punctiliar, one-time events. Sanctification is a progressive, lifelong work. So while the Christian is declared righteous in God’s sight on account of the imputed righteousness of Christ, he has not yet been entirely renewed in his whole being. At least not yet. As Martin Luther said, the Christian is simul justus et peccator—at the same time righteous and sinful. Regeneration makes a man new, yet he is an undeveloped man—a man who is being sanctified but has not yet been perfected.

Already/Not Yet: What Is Happening to Christians (Sanctification—Mortification and Vivification)

Some people, upon conversion, find that many of their old affections and sinful patterns immediately dissolve. Others experience a more gradual renewal of their desires. Although there is a sense that we are sanctified at our conversion, in that we are set apart as holy to the Lord, sanctification as a process is experienced at different rates.

Read More