Since all mankind (our Lord Jesus excepted) is fallen in Adam and pervasively depraved, all people need the last Adam to justify them freely by His death and resurrection (Rom. 5:12–21; 2 Cor. 5:21; Gal. 3:10–14). In Christ, God has delivered His people from “the domain of darkness and transferred [them] to the kingdom of his beloved Son” (Col. 1:13). He has graciously transformed believers through the working of His Spirit, based on the redemption secured by His Son. In his book Human Nature in Its Fourfold State, Thomas Boston explained the extent of the regenerating work of God:
Original sin infects the whole man; and regenerating grace, which is the cure, goes as far as the disease. . . . He gets not only a new head, to know and understand true religion; or a new tongue, to talk of it; but a new heart, to love and embrace it, in the whole of his life.
Far from continuing in a state of being “wholly inclined to all evil,” believers have been renewed by the Spirit of God to do what is “pleasing in his sight” (Heb. 13:21). We can now “walk in a manner worthy of the Lord” (Col. 1:10) and can now “please God” (1 Thess. 4:1). In his letter to Titus, the Apostle Paul explained how the grace of God enables those who have been redeemed to live uprightly:
The grace of God has appeared, bringing salvation for all people, training us to renounce ungodliness and worldly passions, and to live self-controlled, upright, and godly lives in the present age, waiting for our blessed hope, the appearing of the glory of our great God and Savior Jesus Christ, who gave himself for us to redeem us from all lawlessness and to purify for himself a people for his own possession who are zealous for good works. (Titus 2:11–14)
While this is a glorious truth, believers still battle indwelling sin after conversion as part of their sanctification. As the Westminster Confession of Faith states, “This corruption of nature, during this life, does remain in those that are regenerated; and although it be, through Christ, pardoned and mortified, yet both itself and all the motions thereof are truly and properly sin” (6.5).
Romans 6–8 reveals the dynamics of sanctification. In 6:1–23, the Apostle explains that believers have experienced a radical breach with the power of sin through their union with Christ. In 7:13–25, he explains the ongoing battle with indwelling sin. And in 8:1–11, he charges believers to mortify remaining sin by the power of the Holy Spirit. At one and the same time, the Apostle teaches that believers are no longer totally depraved and that the “corruption of nature” remains within them.
When we consider the full-orbed teaching of Scripture about the believer’s relationship with his or her sin, we will have a right understanding of what we were, what we are, and what we one day will be. And we will be able to say with Newton: I am not what I ought to be. I am not what I wish to be. I am not what I hope to be. Yet, I can heartily join with the Apostle and acknowledge, “By the grace of God, I am what I am.”