How can one be “dead to sin” (Rom 6:2) and yet continue to possess its source, which is the “old man” (Eph 4:22; Col 3:9)? It’s scripturally certain that “dead” does not intend the eradication of the sin nature, nor the effects of it, or the Spirit would not need to oppose it (Gal 5:17), and the Apostle Paul would have not discovered its continual indwelling (Rom 7). We are not said to be in the sin nature (Rom 8:9), but it is in us! The sin nature being “crucified” (Rom 6:6) within believers separates (“sanctifies” - 2Th 2:13) them from being “in the flesh,” i.e. not condemned nor dominated by the sin nature (Rom 8:1; 6:12, 14). The crucifixion power of the Lord Jesus is applied to the old man and separates us from the natural desire for sin, which is seen in our prominent motive to continue to “shun evil” (1Pe 3:11).
Rebirth is transformation (Rom 12:2) from being dead in sin (Col 2:13)—to being “dead to sin” (Rom 6:2)! To “continue in sin” (Rom 6:1) is to desire and willingly serve sin, which is the only way one can respond in an unregenerate state, for there is no new nature to desire otherwise.
The Divine Nature of Christ was not created, thus the believer’s “new man” is not Christ’s nature, which has always been, but a nature that was created “after” His nature (Col 3:10), i.e. not in similitude of His deity but in the imputation of His holiness. This nature is the indwelling “seed,” which is that part of us that “cannot sin” (1Jn 3:9). It is the Spirit via the new nature that God “works in you” (Phl 2:13), thus it is the new nature and work of God that keeps those reborn from ever again desiring to sin willingly (Heb 10:26).
Paul demonstrates the indwelling of his new nature by the example of being a “captive to the law of sin” (Rom 7:23). The sense is that any sin committed by his old “I” is against the will of his new “I” (Rom 7:17, 20).
Again, the most significant issue concerning deliverance from sin lies not in the possession of its source nor in the commission of its works—but whether or not it’s the willful desire of the soul to sin!