Absolutely. The FAITH cannot change. However, people within the Church can try to change it. May I point out the Arian heresy as an example of the widespread destruction of faith within the Church? The Faith remained what it was, but within the Church an estimated 90% of Bishops were Arian and therefore were not proclaiming the Faith.
While this is true, it does need a qualification. Language, devotions, liturgy, customs, and pious practices are intertwined with the Faith. They teach us the Faith. They help us believe the Faith. They give us graces to live the Faith. Lex orendi lex credendi. We cannot and must not make a hard-line distinction between Faith and the practice of the Faith. If the Faith is lost, the practices will be lost, too. If the practices are lost, the Faith will be lost, too.
While there are many factors, it cannot be coincidence that at a time when we have seen the most radical changes to Catholic practices, devotions, liturgies, customs, etc, there is also a massive crisis of faith and catechesis.
Perhaps. But there are many more people who need to realize the incredible importance of the things that you list. These so-called externals have been a part of Catholic identity and Catholic culture for so long that the swift and radical change of removal of them has shaken Catholic identity. Luckily the pendulum seems to be swinging back (thank God for Pope Benedict). I can only imagine the sadness and loss felt by many in the 70s when things that were part of Catholic identity (altars, stained glass, statues, devotions, etc, etc) were removed. For some, it must have felt like losing a family member, or getting lost in the woods.
The liberals also believe in lex orendi lex credendi. They are using to change the Faith.
This is too simplistic, brother. We are not dualists (a condemned heresy). Externals and internals are intertwined. One affects the other. One CHANGES the other. Yes, the Deposit of Faith cannot change, but if we change externals we can change the beliefs of an individual about the Deposit of Faith. We can ruin their faith.
Absolutely. Truth cannot change.
Tweeks and massive changes are different things. The Catholic Church has always been a Church of Tradition, meaning that novelty has been looked at with suspicion. When in doubt, She has historically gone with that which is old, not with that which is new. The modern outlook, however, has re-oriented humans towards the future. Progress is in the future, tradition is in the past. We are so inculcated with this modern outlook, living in a modern culture, that we often subconsciously follow it: the new is better, the old is “out-dated.”
It is also dangerous to make the distinction greater than what it has traditionally been.
And I will say pre-emptively that I am speaking of the Catholic Church as experienced by laity, since 99% of us here are not priests or religious.