Which is why the passage in question correctly reads, "ἡ βασιλεία τοῦ Θεοῦ ἐντὸς ὑμῶν ἐστιν," that is to say, "The Kingdom of God is in your midst.”"
Notice how this construction differs from what we find at Matthew 23:26: "καθάρισον πρῶτον τὸ ἐντὸς τοῦ ποτηρίου καὶ τῆς παροψίδος," that is to say, "cleanse first the inside of the cup and of the dish."
midst implies the core, or center of self. it doesn't imply something that is separate from self.
it goes to state of mind. to the state of one's spirit. jesus was speaking to people about their state of minds
even in the translation it implies the interior of something, the center of something, the core,
so if the spirit, the mind counts for everything and the flesh for nothing, then mind is creator of the problem/solution.
Whoever has ears, let them hear what the Spirit says to the churches. that is let them that have ears hear what the mind says to the body
foolish is as foolish does