Pope Pius IX said "If a Future Pope Teaches Anything Contrary to the Catholic Faith, Do Not Follow Him!”

“Pope Francis’ pontificate is like a standard lifted up before Catholic integralists and those who equate material continuity and tradition: Catholic doctrine does not just develop. Sometimes it really changes: for example on death penalty, war." Professor Massimo Faggioli, joint editor of the Oxford Handbook of Vatican II

"The tradition of the church is always in movement." Pope Francis

“Rigidity [in the church] is a sin against the patience of God.” Pope Francis

“Let nothing new be introduced, but only what has been handed down.” Pope Benedict XV

“Nothing new is allowed, for nothing can be added to the old. Look for the faith of the elders, and do not let our faith be disturbed by a mixture of new doctrines.“ Pope St. Sixtus III