Why "Kingdom of God"?

Historians tell us that Jesus and his band could have proclaimed Family of God
Or Fellowship of God. Or People of God. Or Church of God.
Even Synagogue of God. But they did not.

They instead proclaimed, Kingdom of God.
They also preached Good News to the Poor. Liberation to the Captives.
And Peace based on Justice.

All Anti-Imperial rhetoric.
Subversions of the pillars of the Pax Romana.
Scandalous. Dangerous. Rebellious.

Often, you and I forget that we follow an Executed God.