Here are a few excerpts from Cardinal Müller's recent "First Things" article, under the rubric of the gnostic corruption of the faith in Amoris Laetitia.
"Irenaeus...compared Christian doctrine to a mosaic whose stones were arranged to reproduce the image of the King. In his view, the Gnostics had taken the same stones, but had changed their order. Now, instead of the likeness of the King, they have formed the image of a fox, the deceiver.
"One can in fact sin against the Catholic faith not only by denying some of its contents, but also by reformulating its formal principles of knowledge...
"...[T]he pope, as a 'private person' (Lumen Gentium n. 25) or brother among brothers, cannot prescribe his personal theology and lifestyle or the spirituality of his religious order to the whole Church. Obedience as a religious vow is different from the obedience of faith that every Catholic owes to revelation and to its ecclesial mediation. The bishops are bound to obey the pope because of his judicial primacy and not on account of a personal vow they have taken. The papal and episcopal offices are at the service of preserving the unity of faith and communion. Therefore, it is among the pope's and bishops' first duties to prevent polarization and the rise of partisan mentalities.
"All this means that in the exercise of its teaching ministry, it is not enough for the Church's Magisterium simply to appeal to its judicial or disciplinary power as if its teachings were nothing but a matter of legal and doctrinal positivism. Rather, the Magisterium must seek to present a convincing case, showing how its presentation of the faith is in itself coherent and in continuity with the rest of Tradition. The authority of the papal Magisterium rests on its continuity with the teachings of previous popes...
"....[And for bishops' statements] to be orthodox, it is not enough that they declare their conformity with the pope's presumed intentions in Amoris Lætitia. They are orthodox only if they agree with the words of Christ preserved in the deposit of faith. Similarly, when cardinals, bishops, priests, and laity ask the pope for clarity on these matters, what they request is not a clarification of the pope's opinion. What they seek is clarity regarding the continuity of the pope's teaching in Amoris Lætitia with the rest of tradition...
"[Blessed John Cardinal Newman says that in the eyes of the world the Church is] 'a religious communion claiming a divine commission, and holding all other religious bodies around it heretical or infidel; it is a well-organized, well-disciplined body.' This communion 'is spread over the known world; it may be weak or insignificant locally, but it is strong on the whole from its continuity,' and it is 'a natural enemy to governments external to itself; it is intolerant and engrossing, and tends to a new modelling of society; it breaks laws, it divides families. It is a gross superstition; it is charged with the foulest crimes; it is despised by the intellect of the day...And there is but one communion such. Place this description before Pliny or Julian; place it before Frederick the Second or Guizot...Each knows at once, without asking a question, who is meant by it.'"