The kinds of questions I think about — origin of the universe, fundamental laws of physics, that kind of thing — for the most part have no direct impact on how ordinary people live their lives. No jet packs are forthcoming, as the saying goes. But there is one exception to this, so obvious that it goes unnoticed: belief in God. Due to the efforts of many smart people over the course of many years, scholars who are experts in the fundamental nature of reality have by a wide majority concluded that God does not exist. We have better explanations for how things work. The shift in perspective from theism to atheism is arguably the single most important bit of progress in fundamental ontology over the last five hundred years. And it matters to people … a lot.
Or at least, it would matter, if we made it more widely known. It’s the one piece of scientific/philosophical knowledge that could really change people’s lives. So in my view, we have a responsibility to get the word out — to not be wishy-washy on the question of religion as a way of knowing, but to be clear and direct and loud about how reality really works. And when we blur the lines between science and religion, or seem to contribute to their blurring or even just not minding very much when other people blur them, we do the world a grave disservice. Religious belief exerts a significant influence over how the world is currently run — not just through extremists, but through the well-meaning liberal believers who very naturally think of religion as a source of wisdom and moral guidance, and who define the middle ground for sociopolitical discourse in our society. Understanding the fundamental nature of reality is a necessary starting point for productive conversations about morality, justice, and meaning. If we think we know something about that fundamental nature — something that disagrees profoundly with the conventional wisdom — we need to share it as widely and unambiguously as possible.
Arthur C. Clarke, “Credo” (1991)

I’ve never been tempted to murder anyone, or break into their house and steal their stuff. It’s not because I fantasize about it and then think, “Oh, no, I might get in trouble with the government.” It’s because I like my neighbors, like the people in my community, and wish them well — and because I value peaceful, cooperative co-existence. It’s because I have empathy, and can appreciate that other people value their lives as much as I value my own, and could not deprive them of that life without feeling the pain and loss myself.
I don’t need a threat of hell in an afterlife to keep me in line, because I recognize the worth of life in this one.
PZ Myers, “Christians teach me to despise Christianity”, 13 March 2012
