The ENTIRE book of Ephesians is your friend here, St. Thomas.
"To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God,
NEXT VERSE, VERY IMPORTANT HERE
"According to the eternal purpose which he purposed in Christ Jesus our Lord."
What is the "eternal purpose"? Eph. 1:9,10 tells us. "Having made known unto us the mystery of his will, according to his good pleasure which he hath PURPOSED IN HIMSELF..."
"That in the dispensation (I know you hate this word, but hey, it's here, it's not going anyplace) of the fullness of times he might GATHER TOGETHER IN ONE ALL THINGS IN CHRIST, BOTH WHICH ARE IN HEAVEN, AND WHICH ARE ON EARTH; EVEN IN HIM."
So why does He say He purposed this?
Eph. 2:7 tells us.
"That IN THE AGES TO COME He MIGHT SHEW THE EXCEEDING RICHES OF HIS GRACE IN HIS KINDNESS TOWARD US THROUGH CHRIST JESUS."
OH, so it's His GRACE that will be displayed in the ages to come? And what is this grace that He talks about? Do we know? Yes we do.
Eph. 2:8,9: "FOR BY GRACE ARE YE SAVED THROUGH FAITH; AND THAT NOT OF YOURSELVES; IT IS THE GIFT OF GOD; NOT OF WORKS, LEST ANY MAN SHOULD BOAST."
So, there it is. Exactly what God purposed, to whom He purposed it, and WHY He purposed it.
But there's a problem here: GRACE. Does your Church teach Eph. 2:8,9? The Church the Body of Christ does. Does your Church believe that and that alone saves you? The Church the Body of Christ does. If you are teaching or being taught anything other than what GOD HAS PURPOSED, how do you possibly think you are going to be teaching His angels? Really....?
Angels learn about grace through watching the church because grace is not a facet of God that angels can experience, therefore comprehend.