Andrew Brown at The Guardian:
But there remains the question of whether humanism is in fact a religion, or something more like a religion than it is like any other sort of social movement. This is complicated because of the way in which “religion” has become a toxic brand. But if we go back to the science, I think the answer is clearly that it is. Emile Durkheim, who pretty much founded the scientific study of religion, defined it as “a unified set of beliefs and practices relative to sacred things, that is to say, things set apart and surrounded by prohibitions – beliefs and practices that unite its adherents in a single moral community called a church”.
So, can you have religions without a church? Humanism almost qualifies. It sacralises humanity, claiming for us a significance that is not to be derived from either biology or physics. Organised humanism clearly has unified beliefs and practices. It even has the world’s most lugubrious and sentimental hymn: John Lennon’s Imagine. Like all modern religions it has universalist aspirations, claiming to explain the lives of non-believers better than they can do so themselves. It can inspire heroism and self-sacrifice, but also be used to legitimise intolerance – see Sam Harris and his friends.