kingdom of God, kingdom of heaven

Definition

Both of these terms refer to God's rule and authority over his people and over all creation. They also refer to the people who are ruled by God.

In the New Testament, the book by Matthew uses the expression "kingdom of heaven" to refer to the "kingdom of God." Both terms mean the same thing.
The Old Testament prophets said that God would establish his kingdom by sending the Messiah to rule with righteousness and to conquer his enemies.
Jesus, the Son of God, is the Messiah who will rule over God's kingdom.
The spiritual kingdom of God has always existed in heaven because God has always reigned there.
The physical kingdom of God will be established on earth when Jesus returns from heaven to rule as the Messiah forever.