Gounod's "O Divine Redeemer." We used to sing this in church once in a while, not really so much now. You will never hear it more beautifully sung than this.
P.S. It's a habit by now. This hearing in church would have happened long, long ago. It cannot be certain even that I heard it more than once. I know that I remember only the chorus from "O divine redeemer", but I remember it exactly, along with all the words which were the same as these. The minds of the young are remarkable. Try to give them something important to remember.