Date: May 18, 2017 06:47AM
A lot of hymns are public domain, and various denominations have used them, putting their own lyrics en toto, or taking others and tweaking them a bit so the words are consistent with their doctrine. A very common practice. This is facilitated in that much hymn music employs similar meter and harmonic structure.
"Be Still My Heart," with melody from Sebelius' "Finlandia," is found in many, many hymnals, A number of lyrics, among them "Glorious Things of Thee Are Spoken" are set to the second movement of Hayden's String Quartet #76, Opus 62, #3 including the Austrian national anthem, and the Nazis' (Deutschland Uber Alles):https://www.youtube.com/watch?v=mBmCcSz6HWw
It's often stated that Hayden should have saved this theme for a full orchestra, and not a quartet--it's just "too big," as if Pasternak had tried to put "Dr. Zhivago" into a short story.