64 One of the outstanding manifestations of this religious unity, and a happy augury for the future, is that altogether unexpected, but well-known fact of which you have knowledge, Venerable Brothers, a fact not pleasing to some perhaps, but certainly very consoling both to us and to you, namely, that recently the representatives and rulers of practically every nation, motivated by a common and instinctive desire for union and peace, have turned to this Apostolic See in order to bind themselves closer to Us or to renew in some cases the bonds of amity and friendship which had joined us together previously. We rejoice at this fact, not merely because it increases the prestige of Holy Church, but because it is becoming increasingly evident on all sides, and especially from actual experience, what great possibilities for peace and happiness, even here below, such a union with Us possesses for human society. Although the Church is committed by God, first of all, to the attainment of spiritual and imperishable purposes, because of the very intimate and necessary connection of things one with another, such a mission serves likewise to advance the temporal prosperity of nations and individuals, even more so than if she were instituted primarily to promote such ends.
Source: Ubi Arcano Dei Consilio (Vatican.va)