47 It is apparent from these considerations that true peace, the peace of Christ, is impossible unless we are willing and ready to accept the fundamental principles of Christianity, unless we are willing to observe the teachings and obey the law of Christ, both in public and private life. If this were done, then society being placed at last on a sound foundation, the Church would be able, in the exercise of its divinely given ministry and by means of the teaching authority which results therefrom, to protect all the rights of God over men and nations.
Source: Ubi Arcano Dei Consilio (Vatican.va)