I was recently reminded of this piece by Morten Lauridsen, "O Nata Lux." It's part of his Lux Aeterna suite, and includes the main motif. I sang it once, and it was transcendent to be an inner voice within these stunning chords.
"O Nata Lux" is the office hymn for the Litugy of the Hours for Lauds (morning prayer) for the Feast of the Transfiguration. It is very, very old.
Listening to it can lift you up, and float you away, whatever your own beliefs are . . .