Besides that kingdom of which He will say in the end, “Inherit the kingdom prepared for you,” though in a very inferior manner, the present Church is also called His kingdom, in the which we are yet in conflict with the enemy until we come to that kingdom of peace, where we shall reign without an enemy.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: City of God, book xx, ch. 9