I see the book of Ephesians and for that matter it's author, Paul, as more than theology.
I have begun to see an incredible love story, written by a loving God, and expressed by a man given the grace by this God, to love a people that in his earlier life, he could not have even had a meal with.
These people, the Gentiles, were always considered as somehow 'lesser' and alienated from the God of Israel.
Paul is given the responsibility to reach into the nations (Gentiles) and bring a remnant in.