Do we just have to put up with this? Is there an inevitable choice to be made between dogmatic rigorism and a humane, kindly relativism? I think that in the theories we have just been talking about, there are three things people have not thought through carefully enough. First of all, religions (and nowadays, also agnosticism and atheism) are seen as being all of the same kind. But that is by no means the case. There are in fact sick and degenerate forms of religion, which do not edify people but alienate them: the Marxist criticism of religions was not entirely based on delusions. And even religions whose moral values we must recognize, and which are on their way toward the truth, may become diseased here and there. In Hinduism (which is actually a collective name for a whole multitude of religions) there are some marvelous elements – but there are also negative aspects: involvement with the case system, suttee [self immolation] for widows, which developed from beginnings that were merely symbolic; offshoots of the cult of the goddess Sakti – all these might be mentioned, to give just a little idea. Yet even Islam, with all the greatness it represents, is always in danger of losing balance, letting violence have a place and letting religion slide away into mere outward observance and ritualism. And there are of course, as we all know but too well, diseased forms of Christianity – such as when the crusaders, on capturing the holy city of Jerusalem, where Christ died for all men, for their part indulged in a bloodbath of Moslems and Jews. What that means is that religion demands the making of distinctions, distinctions between different forms of religion and distinctions within a religion itself, so as to find the way to its higher points. But treating all content as comparably valid and with the idea that all religions are different and yet actually the same, you get nowhere. Relativism is dangerous in quite particular ways: for the shape of human existence at an individual level and in society. The renunciation of truth does not heal man. How much evil has been done in the name of good opinions and good intentions is something no one can overlook.
—Cardinal Joseph Ratzinger, Truth and Tolerance: Christian Beliefs and World Religions. Trans. Henry Taylor (San Francisco: Ignatius Press, 2004), 203-4.