Pope Pius IX (1846–1878), Allocution Singulari quadam, December 9, 1854: ... as is Our Apostolic Duty, we wish your episcopal solicitude and vigilance to be aroused, so that you will strive as much as you can to drive form the mind of men that impious and equally fatal opinion, namely, that the way of eternal salvation can be found in any religion whatsoever... "For, it must be held by faith that outside the Apostolic Roman Church, no one can be saved
Pope Pius IX (1846–1878), Encyclical Singulari quidem March 17, 1856): "Teach that just as there is only one God, one Christ, one Holy Spirit, so there is also only one truth which is divinely revealed. There is only one divine faith which is the beginning of salvation for mankind and the basis of all justification, the faith by which the just person lives and without which it is impossible to please God and come to the community of His children. There is only one true, holy, Catholic Church, which is the Apostolic Roman Church.