the services of any "Church of Iúvatar" would consist entirely of music.
An interesting concept, sir Whitfoot.
Yet...consider this. (The 'literalist' in me rises.)
All the 'important'
concepts of communication between
Eru and the
Ainur were (essentially) 'verbal'. "Here are 3 themes. Sing about them and embellish them "if you wish". (He introduced the concept of 'choice' verbally as well.)
So they sang. And of course, there's the wonderful combat between self-will and other-will in view.
Then Eru SAYS "follow me out and see what you've done."
So they follow him.
And he SAYS
"Let these things BE."
Once that "Be" is done, the singing is ended. It has achieved its purpose. All their "individual singing' and 'slowly learning to sing in groups' prior to that Song was just the training ground.
Now that it's "done" we see the Ainur and
Maiar always TALKING. The role of the
Valar is to 'go and make what you've sung'. Not to continue singing over it.
There is one who sings
Melkor to sleep at one point... and of course the
Elves like to sing all the time... but still the most important thing in 'communicating needs, concepts, etc.' to one another is Talk, not song.
So I dunno. I would think a Church of
Iluvatar would be pretty much like any other church.
The species would find numerous ways to 'worship', including eventually bending it all into some distorted thing that looks nothing like its beginnings did to begin with. (The path taken by virtually every 'church' existing today.)
We have a history of distorting truth to match our preference, rather than changing our preference to match truth. I don't see that changing., especially as the Religion of Opinion comes to the fore now to rule the day.