Liberal Religion is the "religion with no name" that replaced that Medieval conception, by making an unstated shift in the premise. The purpose of humanity is human well-being. For almost all human beings since the dawn of time, with the exception of professional theologians, this has been pretty obvious. Liberal Religion was created in the Western tradition by this shift from theo-centric worldview to a human-centric worldview. And that shift was connected with a turn toward empiricism and science as the primary way of knowing and understanding the world.
My assertion in the previous post "The Mission of Liberal Religion Is.." liberal religion was human-centered was speaking to this distinction. One of my oldest friends in the world chided me for being 'species-ist' by this statement in a comment on Facebook. I think that our enlightenment forebears were species-centric, but we don't have to be. My colleague, Clyde Grubbs, similarly points out the narrowness of the enlightenment world view which pulled the isolated intellect out the world to observe it from afar. True, but we don't have to go backwards to pre-modern theological scholaticism to escape that blind alley.
Human-centered worldview could be and has been summarized by the word "humanism". Unfortunately, the word "humanism" has become the trademark of atheism, especially in UU circles, so it has been narrowed. In this context, I am using it to mean a human (and all life-centered) worldview as opposed to what was dominant before.