1 John 3:8 He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.Greetings again to all in this thread. Thank you for sharpening me and correcting me when you think it is needed.
I thought, to help shed light on the OP, I might zoom out and provide an overall structure to the assertion that one of the purposes of the Incarnation was to destroy the power of sin.
(Rom 8:3 NKJV) 3 For what the law could not do in that it was weak through the flesh, God [did] by sending His own Son in the likeness of sinful flesh, on account of sin: He condemned sin in the flesh,
So according to Rom 8:3, what the "law could not do" means that the law was part of God's stratagem to do something. But it was never intended to be the only tool. So what the law could not do, God sent His Son to do. So what was His Son sent to do that the law could not? He was sent to "condemn sin" (Rom 8:3). But didn't the law condemn sin?
Justice, through the law, rightly conquers the sinner and puts the sinner under the foot of God. But the power and effects of sin have not been conquered by justice, only the sinner has been put under the foot of God the Son through the law. The power of sin and its effects goes unchecked, for sin brings death and justice ensures death; sin brings alienation and justice seals that alienation; justice in some ways even works in accordance with the outcomes to which sin aspires (1Cor 15:56), i.e., the condemnation and penalty placed upon mankind. As the Scriptures say, "the strength of sin is the law" (1Cor 15:56).
God’s decree to give the written law was “because of transgressions” (Gal 3:19). These transgressions ran rampant, causing alienation and bringing death (Rom 5:14) and were left unchecked because “sin is the transgression of the law” (1John 3:4) but “where no law is, [there is] no transgression” (Rom 5:14 KJV), and “sin is not imputed when there is no law” (Rom 5:13).
The salvo of God’s laws to declare the battle lines and to put all things under His feet, starts with the law that confines and defines transgression, through the “knowledge of sin” (Rom 3:20, Rom 7:7); it spotlights sin, so in the light the “offense might abound” (Rom 5:20); therefore being a “tutor” (Gal 3:24), a guide toward the object of this world’s purposeful end, which is the Son of God.
The law therefore condemns the sinner so that “all the world may become guilty before God” (Rom 3:19, Gal 3:11). This is a step in the reconciliation between God and mankind. But where the law was strong accounting for the sinner, the law is weak in accounting for sin. But within God's stratagem, where the law is weak to account for the power of sin, God sent “His own Son in the likeness of sinful flesh, on account of sin” (Rom 8:3), and by the decree of the Incarnation, through His blood and resurrection, He conquered sin in the flesh (Rom 8:3) where the law could not (Rom 8:3).
In this sense, Christ is the completion of the law. The final nail in the stratagem to "destroy the works of the devil" (1John 3:8). In which John says is one reason why the "Son of God was manifested".
Peace to your brothers
From before the creation of Adam was it the intent of God [the Father] to do the above in bold through Adam? Consider:
because of this, even as through one man the sin did enter into the world, and through the sin the death; and thus to all men the death did pass through, for that all did sin; for till law sin was in the world: and sin is not reckoned when there is not law; but the death did reign from Adam till Moses, even upon those not having sinned in the likeness of Adam's transgression, who is a type of him who is coming. Rom 5:12-14
Why was Adam created of the flesh? Was it because the devil did sin from the beginning and needed to be destroyed?
Just some thoughts I have had.