The temptation for Christians in modernity is to equate the kingdom with ideals that we assume represent the best of human endeavor: freedom, equality, justice, respect for the dignity of each person. These are all worthy goals that Christians have every reason to support, but goals that are not in themselves the kingdom. To equate these ideals with the kingdom is to separate the kingdom from the one who proclaims the kingdom. "Jesus is Himself the established Kingdom of God" (Barth). Or in Origen's classical phrase, Jesus is the autobasileia--the kingdom in person.
Hauerwas, Matthew, Brazos Theological Commentary on the Bible