Richard Beck, in his series discussing "The Gospel According to Ta-Nehisi Coates" (particularly in reference to Coates' book Between the World and Me), says this about what Jesus' kingdom looked like:
Jesus, by contrast, created communities centered around giving care to the most vulnerable in his society. Jesus carved out of Empire space that protected and cared for the most fragile bodies. That's what Jesus did as he moved from town to town, he created a community where the most oppressed and marginalized were welcomed and cared for. Communities of care that were open to agents of Empire, tax collectors and Roman soldiers, who were willing to work to buffer fragile bodies.
And this is what the early church did as well. The church carved out of Empire communities of care. Imperial Rome knew Christianity to be religion popular with women and slaves because of how these communities buffered their fragile bodies from the ravages of Empire.
To my eye, these communities of care carved out of Empire are what Jesus meant when he said "the kingdom of God is in your midst."
(source, emphasis added)
Read the rest of the article (the really good stuff is in the latter half of the post).
Read the series from Part 1.