1Corinthians 15:28 “And when all things are subjected to him, then the Son himself will be subjected to the one who subjected everything to him, so that God may be all in all.”
I personally think that the fifteenth chapter of 1Corintians is mis-understood with too much read into it. We are now living in the days of the All in All. If God is our father and Jesus taught that metaphor to be truth, then our Father is the All in All. If you look at New Testament Prophecy in the way it was written, you will see that it was meant for the first century believers. It was pointing to the destruction of the temple and Jerusalem and the dispersion of the Jews. You can find all of the many posts that show this at this link; it is the link that shows all of the posts that discuss and include eschatology.
The Psalmist said the following: (Psa 110:1) “Here is the LORD's proclamation to my lord: "Sit down at my right hand until I make your enemies your footstool!" Who were Jesus enemies? It was the Sanhedrin. It was the rulers and authorities, principalities and powers of second temple Judaism. How did God make Jesus enemies his footstool? He used Titus of Rome to destroy the temple and Jerusalem, and disperse the Jews away from Judea. Jesus enemies were in fact made his footstool in 70CE. He was exonerated. His prophecies were proven to be true. All things were put under his feet including death. The sting of death was sin. The power or strength of sin was the law. The last enemy was the death brought about by the law. Christ provided the victory over death with the assurance of eternal life. Once Jesus had proclaimed eternal life, had risen from the dead to prove it --- death lost its sting. But, when the temple was destroyed, the ministry of death was destroyed along with it, and all things, including his enemies and death were put under his feet.
That being the case, the kingdom has been turned over to the Father so that the Father is the All in All. Jesus prayer is answered; (John 17:23) I in them and you in me — that they may be completely one, so that the world will know that you sent me, and you have loved them just as you have loved me. It is not necessary to see a distant eschatological future fulfillment. It is current reality. The kingdom is now and we are to be manifestly the children of God now. The fact is that we have become partakers of the divine nature and have been given all we need for life and godliness. The problem is that we must realize and believe it. This will only come as more and more people embrace the provision of God’s grace and rest in our eternal connection.
Isn’t it a shame to be waiting for what is already here? If believers would corporately re-enforce one another in resting in God’s grace, it would be possible to experience the All in All continually. It is so simple… all that we need to do is shift our paradigm.