As a Catholic, I am in full agreement with what the Church has always taught on this issue.
"The following statements on Outside the Catholic Church There is No Salvation are from the highest teaching authority of the Catholic Church. They are ex cathedra Papal decrees (decrees from the Chair of St. Peter). Therefore, they constitute the teaching given to the Catholic Church by Jesus Christ and the Apostles. Such teachings are unchangeable and are classified as part of the solemn magisterium (the extraordinary teaching authority of the Catholic Church).
Pope Innocent III, Fourth Lateran Council, Constitution 1, 1215, ex cathedra:
“There is indeed one universal Church of the faithful, outside of which nobody at all is saved, in which Jesus Christ is both priest and sacrifice.”
Pope Boniface VIII, Unam Sanctam, Nov. 18, 1302, ex cathedra:
“With Faith urging us we are forced to believe and to hold the one, holy, Catholic Church and that, apostolic, and we firmly believe and simply confess this Church outside of which there is no salvation nor remission of sin…Furthermore, we declare, say, define, and proclaim to every human creature that they by absolute necessity for salvation are entirely subject to the Roman Pontiff.”
Pope Clement V, Council of Vienne, Decree # 30, 1311‐1312, ex cathedra: “Since however there is for both regulars and seculars, for superiors and subjects, for exempt and non‐exempt, one universal Church, outside of which there is no salvation, for all of whom there is one Lord, one faith, and one baptism…”
Pope Eugene IV, Council of Florence, Sess. 8, Nov. 22, 1439, ex cathedra:
“Whoever wishes to be saved, needs above all to hold the Catholic faith; unless each one preserves this whole and inviolate, he will without a doubt perish in eternity.”
Pope Leo X, Fifth Lateran Council, Session 11, Dec. 19, 1516, ex cathedra:
“For, regulars and seculars, prelates and subjects, exempt and non‐exempt, belong to the one universal Church, outside of which no one at all is saved, and they all have one Lord and one faith.”
Pope Pius IV, Council of Trent, “Iniunctum nobis,” Nov. 13, 1565, ex cathedra:
“This true Catholic faith, outside of which no one can be saved… I now profess and truly hold…”
Pope Benedict XIV, Nuper ad nos, March 16, 1743, Profession of Faith: “This faith of the Catholic Church, without which no one can be saved, and which of my own accord I now profess and truly hold…”
Pope Pius IX, Vatican Council I, Session 2, Profession of Faith, 1870, ex cathedra: “This true Catholic faith, outside of which none can be saved, which I now freely profess and truly hold…”
Thanks to Most Holy Family Monastery.
Protestantism is indeed a man-made religion for does not have Christ as its founder, but man who rebelled against our Lord’s Church and broke from it.