Despite every attempt by God to make revelation a matter of light and life (that is, positive and inviting), the fallen world prefers darkness to light (see John 3:19). This is precisely the response to be expected from an egoic approach to life.
Egotism (the essence of original sin) must, by its very nature, call its view “light,” and every other view “darkness.” To do otherwise would be to call its own self-centered claims into question. Consequently, the fallen world’s claims to open-mindedness are no more true than any other view that declares itself to be judge and jury over everything else.
Critics of Christianity who claim it diminishes human life are right in two ways: (1) when the expressions of faith (sadly) turn out to represent selfish aims, and (2) when the expressions of faith challenge a definition of “human” that is actually sub-human.
In other words, the light of faith cannot shine in a fallen world without caricature and controversy. But the fact that sinful people (all of us) try to call the light of God “darkness,” does not mean that it actually is.
Reality always looks upside down when you are standing on your head.