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.
O nata lux de lumine, Jesu redemptor saeculi, Dignare clemens supplicum Laudes precesque sumere.
Qui carne quondam contegi Dignatus es pro perditis, Nos membra confer effici Tui beati corporis. O Light born of Light, Jesus, redeemer of the world, with loving-kindness deign to receive suppliant praise and prayer.
Thou who once deigned to be clothed in flesh for the sake of the lost, grant us to be members of thy blessed body.
Listening to it can lift you up, and float you away, whatever your own beliefs are . . .