When we say that lex orandi lex credendi est, we mean that the Church’s prayers reveal to us her doctrines, and that salutary doctrine informs our prayer life. This point can be illustrated with any and every teaching of our Faith. In the following prayer, indulgenced by the Sacred Congregation for the Propagation of the Faith under Blessed Pope Pius IX, we see the Church’s insistence on the perennial dogma extra ecclesiam nulla salus (outside the Church there is no salvation):
O Mary, Mother of mercy and Refuge of sinners, we beseech thee, be pleased to look with pitiful eyes upon poor heretics and schismatics. Thou who art the Seat of Wisdom, enlighten the minds that are miserably enfolded in the darkness of ignorance and sin, that they may clearly know that the Holy Catholic and Apostolic Roman Church is the one true Church of Jesus Christ, outside of which neither holiness nor salvation can be found. Finish the work of their conversion by obtaining for them the grace to accept all the truths of our Holy Faith, and to submit themselves to the supreme Roman Pontiff, the Vicar of Jesus Christ on earth; that so, being united with us in the sweet chains of divine charity, there may soon be only one fold under the same one shepherd; and may we all, O glorious Virgin, sing forever with exultation: Rejoice, O Virgin Mary, thou only hast destroyed all heresies in the whole world. Amen.
Hail Mary, three times. An Indulgence of 500 days (S.C. Prop. of the Faith., Dec. 30, 1868; S.P. Ap., March 18, 1936. Raccolta No. 579).
Nota bene: In various publications, we at St. Benedict Center have proposed this prayer as “A Prayer for the Conversion of America.” Unintentionally, this has led to some confusion, giving people to believe that the Holy See authored and indulgenced it exclusively as a prayer for the conversion of America. In the Raccolta it has no title, but appears, with several other prayers, under the heading, “For the Conversion of Non-Catholics” — which explains the title we have given it on our web site.