The Community of Christ, formerly the Reorganized Church of Jesus Christ of Latter Day Saints have as #253 in Hymns of the Saints keep alive an Advent hymn I like very much, “Heir of All the Waiting Ages” written in by Unitarian minister Marion Franklin Ham. (They have a new hymnal in the works, so who knows what the future holds.) Sung to the lovely tune Picardy, more often matched to “Let All Mortal Flesh Keep Silence.”
The 90s-era Quaker hymnal, Worship in Song has it too. I wish it was in a current Unitarian Universalist hymnal; the old red and blue hymnals have it.
The Community of Christ is an interesting church body. In recent years I’ve seen them taking on a less sectarian ethos, and also defining themselves as a Christian peace movement. I also adore their Temple. It is open to the public. The interior is modeled after the sacred spiral geometry of the nautilus shell (its numbers change and yet rise again the same in terms of proportional ratio). The cross is made of fragments of wood from every nation of the world.