Ethelred is right: Lutheranism is the sect that has caused the most damage to civilization throughout the ages, affecting everything from theological doctrine to philosophy to economy to commerce to popular culture, etc. This is, in part, because it synthesized and further transmogrified the errors of the heresiarchs of previous ages (i. e., Pelagianism, nominalism, etc.). It was, in a real sense, an prototype of modernism.

Without Luther, we would not have Kant or Hegel or Nietzsche, nor the anti-economics of "imaginary" money: the anti-Thomistic pseudo-philosophies paved the way for the 19th and 20th century modernists and the anti-economic apparatus now in place has destroyed countless souls by debasing them to materialism, practical naturalism, pragmatism, &c. All that led to whatever was spawned by "Vatican II."

Caraffa is right too: the secular humanism and horizontalist anthropocentrism of the Renaissance caused even the best souls to become tepid and lax, making them weak before temptation and attacks against the Church. It paved the way for the cult of man, which is basically what Luther had initiated in a more efficient manner than previous heresiarchs and knaves.

The sect of Mahomet has flourished only because the above-mentioned events came to pass. Consequently, Catholics were lulled into lamentable torpor and tepidity regarding the holy faith. The great Schism was not so much the occasion of that sect's increase as was the Protestant revolt and the humanism that was its precursor. Lepanto is the best example of how the Church triumphed so gloriously against the Islamist heathen, when a holy Pope reigned and Catholics (as individuals and as communities) had recourse to prayer and corresponded with grace.

Secular humanism and the legacy of Luther have led to the devastation assailing Holy Mother Church, thereby weakening Christian values so as to allow the Mohammedan heathen to swarm all over the once-Christian Occident.