Over the course of two thousand years, the Catholic Church has endured just about everything that can happen to an institution: bad popes, corrupt bishops, heresies, schisms, revolutions, persecutions, decadent monasteries, dissolute clergy and theologians so determined to be original that, in the end, they were the only ones who still understood what they meant.
And yet the Church is still here. Not because Catholics have always been sensible. That would be a rather daring historical hypothesis. The Church survived because, time and again, one remarkable phenomenon occurred: once the smoke had cleared, the quarrels subsided and the intellectual acrobatics exhausted themselves, Catholic orthodoxy proved to have extraordinary staying power. Arius disappeared; Nicaea remained. The Cathars disappeared; the Creed remained. Jansenism, Modernism and dozens of other fashions arrived proclaiming themselves the future and ended up as footnotes. Catholicism has a fairly simple litmus test: continuity. Hence the importance of Tradition, of the faith handed down to us.
