“For as in Adam all die, even so in Christ all shall be made alive. But each one in his own order: Christ the firstfruits, afterward those who are Christ’s at His coming. Then comes the end, when He delivers the kingdom to God the Father, when He puts an end to all rule and all authority and power. For He must reign till He has put all enemies under His feet. The last enemy that will be destroyed is death.” I Corinthians 15:22-26 NKJV
Kingdom refers to the one that already came;
“Pharisees asked Jesus when God’s kingdom was coming. He replied, “God’s kingdom isn’t coming with signs that are easily noticed. Nor will people say, ‘Look, here it is!’ or ‘There it is!’ Don’t you see? God’s kingdom is already among you.”Luke 17:20-21 CEB
To understand this, let us take a look at the meaning of “KINGDOM”.
King – Dominion, meaning, there is a King and there is dominion.
Once an individual let himself or herself be dominated by God, that individual becomes the kingdom of God. Meaning, kingdom refers to the believers and the King to whom they believe and trust to dominate them, they are called kingdom because they let themselves by free will be dominated by the King who is God. It does not matter what or who, i.e Angels, Man, Christ. Everyone who let themselves be dominated by God, that someone is God’s kingdom.
The Christ was in a sense God’s kingdom because He is being dominated by God, He let Himself be subjected or be dominated by God. That is why He said, the kingdom is among you.
The Son who is the Christ that carries the NAME and authority of the Father is the deliverer of those other believers or kingdom.
“Then comes to an end”– this refers to the death of the believer who is being dominated by God. Once the believer dies or the kingdom, that individual will be delivered to the Father by the Son.
But, before that;
All rule and all authority and power– this refers to a worldly rule, authority, and power that ruled and have authority over an individual. Jesus will end it, meaning, that individual will have no other ruler, authority and will not acknowledge any other power other than Jesus. This is where an individual become the kingdom of God.
“For He must reign till He has put all enemies under His feet” – meaning, within you, Jesus must reign or govern until all enemies meaning, not only other ruler and authority but our sinful nature is destroyed. And, the last enemy to be destroyed will be death, meaning, Jesus who is in you will destroy death so that, you may be made alive not necessarily in the world but in a spiritual world.