“making known to us the mystery of His will, according to His good pleasure which He purposed in Him as a plan for the fullness of time to sum up all things in Christ — that which is in the heavens and that which is on the earth, in Him.”
Why does God reveal the mystery of the Gospel to us? Is it because he loves us? Is it because we deserve to know? Is it because we are special? Is it because he wants us to choose him? No, none of the above. There is one primary reason according to the Apostle Paul…it is God’s good pleasure. There is nothing outside of himself that compels him to do any of this; instead it pleases him to do so. And yes, he purposed this (intended this, foreordained this, he planned it before the foundation of the earth) and then revealed it in the fullness of time.
Probably one of the most significant clauses in these verses is one that might go overlooked. That is that all things are “summed up” in Christ. Our English Bibles translate this phrase variously — often communicating the idea of all things finding their unity in Christ or finding their fullness in Christ. The word in question is ἀνακεφαλαιόω (anakephalaio’o), which means “to sum up (as in math), to recap, or to summarize.” It is used only one other time in the New Testament, and that is in Romans 13:9, where Paul is speaking about the summary of the second table of the Law (commandments 5-10) being “summed up” in the statement, “Love your neighbor as yourself.” Interestingly enough, in Greek literature outside of the New Testament, this word is often used in conjunction with the Law (c.f. Aristotle and Dionysius of Halicarnassus).
So, what do we do with this? What does it mean that all things in heaven and on earth find their summation in Christ, particularly in terms of the Law? The direct answer is that the only redemption that can be found, in heaven or on earth, is the redemption worked by Jesus Christ. He has fulfilled the Law on behalf of His elect and the result of that is that he is the steward of creation and will redeem creation from the effects of the Fall of Adam (Romans 8:20-23). This interpretation also fits the context of the rest of the paragraph before it, which speaks of Christ redeeming us from our trespasses. All redemption that takes place is by and through Christ. Those who are not in Christ cannot find themselves to be redeemed, no matter how hard they might try.