I agree that it's important to be conservative when talking about gods. I would never tell anyone that God is a real person who exists within physical substrate (except in my own brain-meat).
But, I also think that "fiction," while technically accurate, fails to capture the way in which I use God. While a "set" of anything is technically a fiction (in that it doesn't exist in the physical substrate), set theory can be a powerful tool. If you were to dismiss any given set as a fiction without first appreciating the details of its use, you would be losing important details.
E: I'm not familiar with Unitarian Universalists. What's their credo?
I agree that God (in the sense I use it) is often polluting of rationality, but that's only because it's so often accompanied with specious metaphysical claims. I don't pray, except in the sense that I meditate on the shape of God.
"A pleasant fiction that makes you feel nice every time you talk about it" captures some of what I mean by God. These systems of symbols are "fictional" in that they don't exist within consciousness and not the external world. However, "pleasant" is underselling it. Having encountered life long spiritual people of all walks of life, I believe that the transformative love, compassion, and openness made possible by building a relationship with a god (or any other spiritual construct) should not be undersold. Personally, I use gods in concert with my meditative practice to cultivate love and joy. "God" can be a terrifically useful and fun move in the consciousness game.
As I said, you can preserve the essential spiritual sense of God while preserving rationality, as long as you're clear that the God you're believing in will not grant wishes, does not have his hand on the pulse of the universe, and never ressurected anyone.
E: having gonw back and read Eliezer's article on doublethink, I think I see why you're concerned.
I'm not advocating for the "happiness of stupidity." It is essential to my view that the game of predicting reality is compatible with the game of maximizing love (I'll shift to "love" rather than "euphoria" because "love" is less suceptiible to decay into damning-with-faint-praise-words like "pleasant.")
Consider this passage in the article you linked: "All that is left to you now, is to aspire to such happiness as a rationalist can achieve. I think it may prove greater, in the end. There are bounded paths and open-ended paths; plateaus on which to laze, and mountains to climb; and if climbing takes more effort, still the mountain rises higher in the end."
Think of spirituality as an exceptionally beautiful mountain on the path of rationality. There is a huge subset of possible human experiences, among which are the best and most valuable, that are captured within spirituality.
I understand being wary of it, because historically spiritual people are often rationally lazy. But refusing to engage with it entirely would be throwing one of the best babies we have out with the bathwater.
I agree entirely. What I am arguing is that gods can be a part of "skills, qualities, attitudes, and habits necessary to handle the truth in a sane and healthy manner."
They don't require belief in any untruths, merely interpretation of the truth into a euphorically beautiful form. No where in my post do I advise believing anything untrue, and nowhere do I advise deliberately ignoring true things.