Reference request for the idea that God create the physical universe in order to demonstrate some truth to angelic and demonic beings

I have read somewhere, not as a doctrinal statement but as a speculation that is not incompatible with basic Chrisian doctrine that some thinkers suggest that God created the physical universe to demonstrate to angelic (and demonic) beings what happens when created beings try living apart from God. The idea is suggested by the passages in 1 Peter 1:12 (even angels desire to look into these things) and Ephesians 3:10 (His intent was that now, through the church, the manifold wisdom of God should be made known to the rulers and authorities in the heavenly realms). I can't locate any reference to this idea now. Can someone help me identify the name of this idea, find a reference for it, and then explain this idea more?