Pope John XXIII
Pacem in Terris §152
Pacem in Terris: On Establishing Universal Peace in Truth, Justice, Charity, and Liberty
152 One may well ask the reason for this, since the men who have largely contributed—and who are still contributing—to the creation of these institutions are men who are professed Christians, and who live their lives, at least in part, in accordance with the precepts of the gospels. In Our opinion the explanation lies in a certain cleavage between faith and practice. Their inner, spiritual unity must be restored, so that faith may be the light and love the motivating force of all their actions.
Source: Pacem in Terris (Vatican.va)