Immortale Dei §19

¹⁹ So, also, as to the duties of each one toward his fellow men, mutual forbearance, kindliness, generosity are placed in the ascendant; the man who is at once a citizen and a Christian is not drawn aside by conflicting obligations; and, lastly, the abundant benefits with which the Christian religion, of its very nature, endows even the mortal life of man are acquired for the community and civil society. And this to such an extent that it may be said in sober truth: "The condition of the commonwealth depends on the religion with which God is worshipped; and between one and the other there exists an intimate and abiding connection."(18)