"For, were the Church in any time hidden and invisible, to whom would men have recourse in order to learn what they are to believe and to do? It was necessary that the Church and her pastors be obvious and visible, principally in order that there might be an infallible judge, to resolve all doubts, and to whose decision everyone should necessarily submit. Otherwise, there would be no sure rule of faith by which Christians could know the true dogmas of faith and the true precepts of morality, and among the faithful there would be endless disputes and controversies. "And Christ gave some apostles, and others pastors and doctors, that henceforth we be no more children tossed to-and-fro and carried about with every wind of doctrine" [Eph 4:11-14]. "
"But what faith can we learn from these false teachers when, in consequence of separating from the Church, they have no rule of faith. How often Calvin changed his opinions! And, during his life, Luther was constantly contradicting himself: on the single article of the Eucharist, he fell into thirty-three contradictions! A single contradiction is enough to show that they did not have the Spirit of God. "
"He cannot deny Himself" [2 Timothy 2:13]. In a word, take away the authority of the Church, and neither Divine Revelation nor natural reason itself is of any use, for each of them may be interpreted by every individual according to his own caprice. Do they not see that from this accursed liberty of conscience has arisen the immense variety of heretical and atheistic sects? I repeat: if you take away obedience to the Church, there is no error which will not be embraced. "

St. Alphonsus D. Ligouri