A point of view to consider
God is God of all....for from Him and through Him and to Him are all things.
Jesus is Lord of all....For it was the Father's good pleasure for all the fullness to dwell in Him, and through Him to reconcile all things to Himself, having made peace through the blood of His cross
He made known to us the mystery of His will, according to His kind intention which He purposed in Him with a view to an administration suitable to the fullness of the times, that is, the summing up of all things in Christ, things in the heavens and things on the earth.
For HE(God) HAS PUT ALL THINGS IN SUBJECTION UNDER HIS(Jesus) FEET. But when He says, "All things are put in subjection," it is evident that He(God) is excepted who(God) put all things in subjection to Him(Jesus). When all things are subjected to Him(Jesus), then the Son Himself also will be subjected to the One(God) who subjected all things to Him(Jesus), so that God may be all in all.
This is a summary of the whole plan of God.
For from Him.....
He is the image of the invisible God, the firstborn of all creation. For by Him all things were created, both in the heavens and on earth, visible and invisible, whether thrones or dominions or rulers or authorities--all things have been created through Him and for Him. He is before all things, and in Him all things hold together.
And through Him
He is also head of the body, the church; and He is the beginning, the firstborn from the dead, so that He Himself will come to have first place in everything. For it was the Father's good pleasure for all the fullness to dwell in Him, (Col 1:18-20)
And to Him are all things
and through Him(Jesus) to reconcile all things to Himself(God), having made peace through the blood of His cross; through Him, I say, whether things on earth or things in heaven.
After all the enemies are abolished there will be no need for "rule, power and authority" for all will be one in the love of God flowing in the glorious liberty of the sons of God, all having settled into their appointed place in the infinite glories of God, in perfect harmony and celebration.
For as in Adam all die, so also in Christ all will be made alive. But each in his own order: Christ the first fruits, after that those who are Christ's at His coming, then comes the end, when He hands over the kingdom to the God and Father, when He has abolished all rule and all authority and power. For He must reign until He has put all His enemies under His feet. The last enemy that will be abolished is death.
When Jesus says God is not the God of the dead but of the living, He is speaking to the deadness of the Pharisees and their separation from God, related to their hostility to God as murderers and scoffers. He is not putting any limitation on the Creator. When Jesus speaks, "Your God and My God", He is speaking to the living, alive in Christ, who know the "I AM". Nevertheless as David writes, "If I make my bed in Sheol, thou art with me". When writers represent things from the point of view of man's consciousness(the dead know nothing) they are not limiting the all encompassing omniscience and omnipotence of the Creator. He is not the God of the dead to the extent that they cannot perceive Him as such and are blind behind the veil of death, carnality and self-righteousness. Yet, he is the Creator of all, and as Paul proclaimed to the assembled philosophers of the nations at Mars Hill(Acts 17:27,28 "...though He is not far from each one of us ... for in Him we live and breath and have our being....for we are all His children". His inclusive language to them was a declaration of grace.