The Roman Catholic Church was the slowest to change.  Change was considered Protestant, a threat to the institution.  For many the implementation of Vatican II was overwhelming, with a lot of misunderstanding.  A change in form does not mean a change in substance.  The unchanging deposit of faith is one thing, but how to present it is another.  The problem is that today the medium is the message.  The Mystery of the Christian message surpasses the possibilities of formulation.  Real development of understanding is natural.  Guided by the Holy Spirit, the People of God, the Church, has retrieved some of the biblical and ancient traditions of the early Church.  This is not a corruption of faith, but a revival of a rich past engaging the world critically.  The Church is always changing using eternal truths in new expressions.