Pope Pius XII
Mystici Corporis Christi §70
Mystici Corporis Christi: On the Mystical Body of Christ
70 These juridical bonds in themselves far surpass those of any other human society, however exalted; and yet another principle of union must be added to them in those three virtues, Christian faith, hope and charity, which link us so closely to each other and to God.
Source: Mystici Corporis Christi (Vatican.va)