"To use the words of the fathers of Trent, it is certain that the Church "was instructed by Jesus Christ and His Apostles and that all truth was daily taught it by the inspiration of the Holy Spirit."[12] Therefore, it is obviously absurd and injurious to propose a certain "restoration and regeneration" for her as though necessary for her safety and growth, as if she could be considered subject to defect or obscuration or other misfortune. Indeed these authors of novelties consider that a "foundation may be laid of a new human institution," and what Cyprian detested may come to pass, that what was a divine thing "may become a human church." -Mirari Vos- Pope Gregory XVI.
"Christ summons the Church to continual reformation as she sojourns here on earth. The Church is always in need of this, in so far as she is an institution of men here on earth. Thus if, in various times and circuмstances, there have been deficiencies in moral conduct or in church discipline, or even in the way that church teaching has been formulated-to be carefully distinguished from the deposit of faith itself-these can and should be set right at the opportune moment." -Unitatis Redintegratio, Vatican II-
-Heresy. The church cannot err in the expression of her dogmas. Vatican I teaches they are irreformable of their nature. Another heresy is that the Church always stands in need of renewal and reformation. Plainly false and contradictory of Pope Gregory XVI.
"Now We consider another abundant source of the evils with which the Church is afflicted at present: indifferentism. This perverse opinion is spread on all sides by the fraud of the wicked who claim that it is possible to obtain the eternal salvation of the soul by the profession of any kind of religion, as long as morality is maintained. Surely, in so clear a matter, you will drive this deadly error far from the people committed to your care. With the admonition of the apostle that "there is one God, one faith, one baptism"[16] may those fear who contrive the notion that the safe harbor of salvation is open to persons of any religion whatever. They should consider the testimony of Christ Himself that "those who are not with Christ are against Him,"[17] and that they disperse unhappily who do not gather with Him. Therefore "without a doubt, they will perish forever, unless they hold the Catholic faith whole and inviolate." -Mirari Vos- Pope Gregory XVI
"But the plan of salvation also includes those who acknowledge the Creator. In the first place amongst these there are the Mohammedans, who, professing to hold the faith of Abraham, along with us adore the one and merciful God, who on the last day will judge mankind. Nor is God far distant from those who in shadows and images seek the unknown God, for it is He who gives to all men life and breath and all things,(127) and as Saviour wills that all men be saved.(128) Those also can attain to salvation who through no fault of their own do not know the Gospel of Christ or His Church, yet sincerely seek God and moved by grace strive by their deeds to do His will as it is known to them through the dictates of conscience." -Lumen Gentium- Vatican II
Heresy: Religious indifference.