The Fallen World System is the administration or un-kingdom alliance of fallen mankind and fallen angels over the First Heavens and the First Earth. The physical creation is an object of redemption, not of destruction. Therefore, the replacing of the Fallen World System with the Kingdom of God is a change of administrations – i.e., the replacing of the administration of fallen mankind and fallen angels with the administration of redeemed mankind and the righteous angels. It takes two realms – heaven and earth – to form a world. The Fallen World System is a “system” precisely because it is the alliance of fallen angels in the heavens above and fallen mankind on the earth below. This system gets replaced, not by doing away with the creation and creating a new physical heavens and earth, but by replacing via transformation the fallen administration with a better system, namely, a redeemed administration of righteous mankind on earth below with righteous angels in the heavens above. Just as Jesus’ body was a resurrected and transformed version of His original physical body, so the New Heavens and the New Earth are a resurrected and transformed version of the new world that replaces the old, originally good, but subsequent ruined version of the world – the First Heavens and the First Earth, which now has become the Fallen World System.
Also see Alliance, Fall, Kingdom, Transformation, and Replace.