It is commonly held that mankind cannot be “at one” with God until Satan is bound. Consider, though, how much this belief diminishes God's power while elevating the status of the wicked one. God will bring all those alive during the Millennium to salvation without Satan being around, even as He is perfecting the firstfruits now with Satan around. God is sovereign, and thus neither limited by Satan's presence nor dependent on it.
During Christ's final Passover, He speaks at length about what His upcoming sacrifice would make possible. His confident statements demonstrate that a close personal relationship with God is entirely possible even while Satan is still the ruler of this world. Jesus promises to love and manifest Himself to those who love Him and keep His commandments (John 14:21). He declares that both He and the Father will make Their home with those who love Him (John 14:23). His work allows humans to abide in Him, even while Satan deceives the whole world (John 15:4-5, 7). He assures us that we can have peace in Him, even as the world—under Satan's influence—is against us (John 14:27; 16:33; see also Acts 10:36; Romans 5:1; 8:6; II Corinthians 13:11; Galatians 5:22; Ephesians 2:14-17; Colossians 1:20; II Thessalonians 3:16). He reveals that the gift of eternal life is entirely His to give (John 17:1-3), and there is no proviso regarding Satan's presence. He promises oneness through the Father's keeping (John 17:11, 20-23)—not through Satan's binding. All the things covered in His prayer are not limited to the original disciples, “but also for those who will believe in Me through their word” (verse 20).
Jesus teaches that it is quite possible to be one with the Father and Son without Satan being bound. When we are brought to Christ, He “delivers us from this present evil age” (Galatians 1:4) and “from the power of darkness” (Colossians 1:13). Satan is powerless to stop God's work (see Job 1:10-12; 2:4-6). Since God's converted people are walking proof of oneness with God in the face of the Devil's influence, it makes no sense to conclude that humanity can be one with God only once Satan is bound.
The world needs the same covenant the elect are under now. Satan's binding will be a tremendous gift to those alive during the Millennium, so in no way should it be diminished, as it will remove a great deal of spiritual pressure. But is Satan's influence so vast as to prohibit the Father and the Son from working out Their plan in the Millennium? Certainly not!