Perhaps one of the most mysterious statements in the Bible is that made by Paul in the "Ephesian Letter" (3:10) that "now unto the principalities and the powers in the heavenlies might be made known through the Church the manifold wisdom of God."
At least it implies that the Apostle had been given a very special revelation, for this is one of the things that could never be arrived at by study, reasoning or deduction. What it all means we do not know, but we can see something.
Firstly, we find it difficult to believe that these principalities and powers are the same as those mentioned in Ephesians 6. Why the Lord should want to display His manifold wisdom to the evil powers would indeed be hard to understand. If His all-governing object is the expression and diffusion of His glory in the universe so that worship comes back to Him in adoration, wonder, and amazed rejoicing, then we have the clue to this statement. The Church here is represented as seated together with Christ in the heavenlies, not in the realm of the evil powers, but above them, amongst the angelic hosts. There, intelligences having absolute confidence in the wisdom and ability of God are nevertheless capable of being instructed and learning. They are aware of the unspeakably great and immense problems that have arisen through Satan's interference and man's complicity with him - the problems of man's disrupted and twisted nature; of the resultant power of Satan over him and man's own utter helplessness; the problem of sin, enmity, hatred, pride, selfishness, warfare, death, etc. It is like a mountainous argument built up for God to answer. They are sure that He can do it, but there is breathless suspense as to how He will do it. They behold the Church as the vessel in which He will give the answer. The components of the Church are humanly as manifold and diverse in dispositions, temperaments, natures, and propensities as there are persons. In them by nature are found all the results and effects of the Fall. Then grace gets to work; calls them, chooses them, saves them, sanctifies them, and changes them so that they go altogether "contrary to nature." They no longer do what they used to do. They do what they never would have done. This is operating and developing every day. Grace, grace, grace! The word occurs a dozen times in "Ephesians," and its glorious issue is that "in the ages to come He might show the exceeding riches of His grace... toward us in Christ Jesus" (2:7). So the Church and its members pass into every kind of trial and testing - persecution, reproach, adversity, sorrow, loneliness, disappointment, physical suffering, frustration, etc. - and the reactions through the grace of God are quite other than they would be apart from it.
There, where things are known for their eternal value and right meaning, this "manifold wisdom of God" is causing principalities and powers to worship and glorify God. And because the Church serves Him in this way it is destined to share His glory, and come down "out of heaven... having the glory of God." It can be easily seen how the Cross relates to this. Initially it secures for God the vessel. Progressively as a principle it empowers to put aside all that works against His glory. The Cross lies at the heart of every disappointment triumphantly borne, and every adversity meekly endured.
Because of the great solution which the Cross is to the problem which has filled the universe, angels and archangels and all the host of heaven adore Him Who thought of it - Whose unsearchable wisdom found expression in "Jesus Christ and Him crucified" (1 Cor. 2:2).