We should not think of God’s plan as being about humans alone. Ephesians 1:9-10 shows that God plans, in the fullness of the times, “to unite all things in [Christ], things in heaven and things on earth” (Ephesians 1:9-10). In this case, the Greek term for “unite” means a regathering of all things around one point—namely Christ. At creation, complete unity filled the universe. Then rebellion entered the creation, bringing division and chaos. That sad condition continues in our world … except in one place: Christ’s “one body.” In the church, old enemies—even the strictest Jews and the worst Gentiles—come together in spiritual unity, which the faithful reflect and work to maintain. The church is God’s masterpiece in which His wisdom is on full display in spiritual realms.
[God’s hidden plan was] that through the church the manifold wisdom of God might now be made known to the rulers and authorities in the heavenly places. This was according to the eternal purpose that He has realized in Christ Jesus our Lord (Ephesians 3:9-11).
He has realized His eternal purpose in Christ.
The church is the part of God’s plan that “He has realized.” Next will come the fulfillment of the rest of the plan, when Christ returns at “the time for restoring all the things” (Acts 3:21 cf. Romans 8:21). His return will mark “the end,” when He destroys all enemies, even death itself (1 Corinthians 15:24-26 cf. 2 Thessalonians 1:5-9; 2:8; Psalm 2:9). Final judgment will seal the eternal fate of the devil, with all his allies and subjects in the “lake of fire” (Revelation 20:10-15; 21:8).