Ephes. 3:8-13 (ESV)
To me, though I am the very least of all the saints, this grace was given, to preach to the Gentiles the unsearchable riches of Christ,  and to bring to light for everyone what is the plan of the mystery hidden for ages in God who created all things,  so 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,  in whom we have boldness and access with confidence through our faith in him.  So I ask you not to lose heart over what I am suffering for you, which is your glory.
So that through the church the manifold wisdom of God might now be made known to the rulers and authorities in the heavenly places. God makes his manifold wisdom known through the church. He does this to the rulers and authorities in the heavenly places, the cosmic realm. I say cosmic realm because here Paul is not actually referring to heaven, but to the Spiritual world in general, the rulers and authorities being Satan and his henchmen. (Ephes 6:12). With every soul called into the church, God makes his manifold wisdom known to these rulers and authorities. He rubs it in their face. It vexes them, but God glories in it