Bishops urge pastors to care for the devotional life of the Church:
136. Strive then, Venerable Brethren, with your customary devoted care so the churches, which the faith and piety of Christian peoples have built in the course of centuries for the purpose of singing a perpetual hymn of glory to God almighty and of providing a worthy abode for our Redeemer concealed beneath the eucharistic species, may be entirely at the disposal of greater numbers of the faithful who, called to the feet of their Savior, hearken to His most consoling invitation, “Come to Me all you who labor and are heavily burdened, and I will refresh you.”[Matt. 11:28] Let your churches be the house of God where all who enter to implore blessings rejoice in obtaining whatever they ask[Cf. Roman Missal, Collect for Mass for the Dedication of a Church] and find there heavenly consolation.
Remember this document was written after the Second World War. Hope was high.
137. Only thus can it be brought about that the whole human family settling their differences may find peace, and united in mind and heart may sing this song of hope and charity, “Good Pastor, truly bread – Jesus have mercy on us – feed us, protect us – bestow on us the vision of all good things in the land of the living.”[Roman Missal, Sequence Lauda Sion in Mass for Feast of Corpus Christi]
I don’t know that Christian prayer would have been any less earnest and intense after WWI, or after/during/before the other devastating wars among Christians in Europe. But Pope Pius XII is right: prayer is the only clear way when the obstacles of human stubbornness and sin and obfuscation seem to dominate the mortal enterprise. Check Mediator Dei on the Vatican web site.