On the one hand the context is the internal workings of the church as v5 "one baptism", and v7 "each one of us" members of the church. On the other hand God cannot shape the development of the church if He is not in charge of "all" the outside influences which bear down upon those inside. Whereas other verses may tell us that God is in charge of the rulers and authorities outside the church, does "all" in Eph 4v6 refer to these or just the internal workings of the church? e.g. unity of the Spirit, baptism and giving of gifts.
The passage in Ephesians you clearly and correctly point out is referring to all in the body of Christ or the Church.
“But to all who did receive him, who believed in his name, he gave the right to become children of God, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God.” John 1:12-13 ESV
People born of the will of God who first receive and then believe, are then and only then regenerated and allowed to become part of the all. Faith proceeds regeneration.
Where does it say that God has power over all? Power and authority are different. Power is strength if you will but authority is legal right.
“And Jesus came and said to them, "All authority in heaven and on earth has been given to me.” Matthew 28:18 ESV
He has all the legal rights and this after the resurrection from the dead.
Eph. 3:20 says:-
"Now to the one who is able to do, exceptionally beyond all things, what we are asking or are perceiving, according to the power which is working in us, 21 the glory is to him in the congregation."
Here Paul is addressing only the Christian Congregation (Church) thus Ch 4 vvs 1-7 is only addressed to the Christian Congregation (Church) not to outsiders as vs 7 says:-
"4:7 Now the grace was given to each one of us according to the measure of the gift of the Christ."
These "gifts" are not for outsiders, thus 4:6 address's only Christians.
Bible quotes are from 'mlvbible.org.'