God is spirit, and his worshipers must worship in the Spirit and in truth (Jn 4.24 NIV) is what Jesus told the Samaritan woman at the well who sought from Him living water. Of course, since the material and spiritual rulers were created by Him and for Him (see Col. 1.16), He could enter the physical realm and appear in various forms to His people before the incarnation. In the text of the bible, He appeared to Abraham, Jacob, Moses, Joshua, and others. In the O.T. He was often referred to as the ‘Angel of the Lord,” which signifies the idea of agency or being “sent.”
Christ will bring the created world (materiality) into His subjection: He who descended is the very one who ascended higher than all the heavens, in order to fill the whole universe (Eph. 4.10 NIV). If He created it, why does He need to fill it? Because the original creation became “topsy turvy,” (tohu wabohu-Gen. 1.2). Chaos and darkness ruled material creation and defiled some parts of the heavens too: And when my sword has finished its work in the heavens (Is. 34.5a NLT). The heavens are now defiled since evil spiritual authorities continue to access it: if even the heavens are not pure in his eyes (Job 15.15b NIV). Satan rules the immediate heaven that envelops the earth: in which you used to live when you followed the ways of this world and of the ruler of the kingdom of the air (Eph. 2.2a NIV). There is a hierarchy of evil under the devil extending to the lower heavens (plural): the spiritual forces of evil in the heavenly realms (Eph. 6.12b NIV). God will one day cleanse the heavens of this evil: but he was defeated, and there was no longer any place for them in heaven. And the great dragon was thrown down, that ancient serpent, who is called the devil and Satan, the deceiver of the whole world—he was thrown down to the earth, and his angels were thrown down with him (Rev. 12.8-9 NIV).
Satan, in the Garden of Eden, sought to thwart God’s plan of giving humans immortality, and thus replacing the fallen angels (see Lk. 20.36). He did this by tempting Adam to sin (resulting in Adam’s death). Christ, the second Adam, demonstrated His love in receiving sin’s penalty, and thus freely redeeming humanity by conquering death. Here is an article by Joe Rigney on God’s simplicity where he concludes by noting the incarnation. This study of God’s attributes and His redemption of humanity leads us to praise and glorifying Him (doxology).Everything in God Is God: How to Think About His Attributes | Desiring God