The denial of God—or the blithe bracketing of the question of God—is not a harmless parlor game. Rather, it carries with it the gravest implications. If there is no God, then our lives do indeed belong to us, and we can do with them what we want. If there is no God, our lives have no ultimate meaning or transcendent purpose, and they become simply artifacts of our own designing. Accordingly, when they become too painful or too shallow or just too boring, we ought to have the prerogative to end them. We can argue the legality and even the morality of assisted suicide until the cows come home, but the real issue that has to be engaged is that of God’s existence.
--Bishop Robert Barron, Vibrant Paradoxes: The Both/And of Catholicism