here (and see combox):
In fictional works by Poul Anderson, we read about:
the Cosmic religion
the Ythrian New Faith
the Johannine Church
SM Stirling presents the Anglo-Indian religion of the Angrezi Raj, the debased cult of the Peacock Angel (see here and here), a Theosophical "Church Universal and Triumphant" and a Wicca that is more neo- than pagan (see combox here).
Robert Heinlein presents the Angels of the Lord, the Fosterite Church of the New Revelation (for both of these, see here) and a new Martian religion.
at least two of these cases, Cosmenosis and Wicca, it is possible to
get into discussing whether these are viable world-views. Do the Wiccan
Gods literally exist in this alternative history of Stirling's? A "Son
of God" is a divine agent. "The Sword of the Lady" would be also.