Right, and if we translate it this way as the power to rule with, or have God rule over, or have God's will for you here as it is in Heaven, then a whole lot of scriptures make sense.
But if I with the finger of God cast out devils, no doubt the kingdom of God (Power, rule and will of God) is come upon you.
(Luk 11:20)
Hi- yes we are under the authority of Jesus's power as Christians. God rules our lives now. But we have to collectively look to God's coming world dominion when the basileia will be fully established.
Most of the time when basileia is used it denotes a literal Kingdom- Matt 25:34, Rev 20"4-6
Jordan, a middle Eastern country is a Kingdom- a literal place
In simple terns, the Magic Kingdom is a place we go to at Disney world- a literal place.
A Kingdom must have a ruler, subjects, laws and territory.
we are experiencing God's sovereignty in our lives now but Revelation shows us we will be living
and reigning with Him in a literal Kingdom (territory) after the second coming of Christ.
When Jesus was telling the Pharisees the " Kingdom of God is within you " He could not be meaning
that God's Kingdom was within them, after all they wanted to destroy Him.
We are heirs of the Kingdom-thy Kingdom come-and that inheritance doesn't come until after Christ returns.