Verse 28 tells us what God is moving all of His creation toward, which is that the Father will be all in all. Everything will be focused on Him, subject to Him, and ultimately in alignment and agreement with Him. And if the whole creation is in agreement with the Father, there will be harmony because everyone will also be in agreement with everyone else. That is almost impossible to imagine these days.
This view of the overarching work of God teaches us that God’s plan, including His creation of mankind, was and is about God, not man. Even the church, with as significant as it is, was instituted for God’s satisfaction and pleasure, not for its own sake.