City Of God

From BiblePortal Wikipedia

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [1]

one of the names of ancient Jerusalem ( Psalms 46:4), and its appropriateness is evident from  Deuteronomy 12:5.

Holy City The sacredness of the Temple extended itself in some measure over the city, and hence Jerusalem itself was called the Holy City, and is so distinguished in the East at the present day ( Nehemiah 11:1;  Daniel 9:24). (See Jerusalem).

The Nuttall Encyclopedia [2]

Augustine's name for the Church as distinct from the cities of the world, and the title of a book of his defining it.

References