22 The Church has always impressed on the minds of her children that declaration of the Divine Redeemer: "Render therefore to Caesar the things that are Caesar's and to God the things that are God's." We call it a declaration because these words make certain and incontestable the principle that Christianity never opposes or obstructs what is truly useful or advantageous to a country.
Source: Ad Apostolorum Principis (Vatican.va)