Purple Alien espouses liberal religious doctrine
A purple alien with a chipmunk voice reprimands humanity for its evil ways and demands that humanity follow certain moral principles before being allowed to join galactic civilization. These principles just happen to be the guiding principles of Unitarian Universalism.
While it's fun to fantasize that there is a multi-species civilization of UU aliens out there, I think this falls into the common science fiction/religious fallacy of imagining a higher power that just happens to share all of your own values. It's just as likely that the galaxy is populated by religious nutcases. In fact, if the ratio of liberal religionists to fundamentalist fanatics on Earth is any indication of the distribution of such beings in the universe at large, it's far more likely that the universe is populated with the Taliban than with Unitarian Universalists.
Of course, my hope is that dogmatic religion is a delusion unique to our species. So far, we've been spared religious idiocy from outer space, (though some religions claim alien influence), but the terrestrial varieties of theological foolishness are pernicious enough.