Forasmuch then as the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death he might destroy him that had the power of death, that is, the devil. (Heb. 2:1)
When Adam sinned and forfeited life from God, he not only died spiritually, but the entire earthly realm over which God had given him dominion was put under a curse.(Gen. 3:17)
From that point, nothing could be produced out of the earthly realm that was spiritual. And even the physical that was produced required a great deal of struggle. In addition, Satan was cast down to the earthly realm. He is the god of this world, with access to all that is earthly.
Jesus Christ became a human being and lived a sinless life. He brought the human being into the fullness of what originally intended for Adam. Then He offered Himself to bear the sin of the world – really to bear all that is earthly pertaining to humankind. This all died when Christ died. What was raised was a new man in Christ. Death had severed the old creation, and resurrection in Christ had birthed the new.
So what we see is that those who are in Christ have a life inside of them that is not of this earthly. Satan therefore does not have access – indeed it is resurrection life which is victory over Satan in every way. But Satan does continue to be able to approach the
natural man that continues to exist in us outside of our union in Christ.
The point is this: The ground of Satan, or his point of access, has been cut out from under him. Not by obliterating it, but by joining us to the Lord in Spirit. The Christian life is therefore one of living FROM new ground — His victory of resurrection life. The only
power that remains for Satan is that of deception. This is why we must know Truth.