He singlehandedly introduced that song into German Catholic and Protestant masses/liturgy.
I only saw that film once in the 60ies, never again, but that song stuck with me forever and I'm not even religious. By the late 60ies it cropped up in church all the time and is now a staple song (generally started in the German pronounciation, but by the end most people sing it like in the movie). And to this day I pronounce
amen in English like Sidney does in the movie as "ay-men" (he sings it like that even in German dubbed versions) and not as "uhmenn". (Just like Mark Twain's Tom Sawyer & Huckelberry Finn has led me to say more often than not "Ay-rab" rather than ""uhrab" for
Arab - in the book always spelled as "A-rab" - before I laughingly catch myself.
)
My mother probably considered The Defiant Ones (German title was more descriptive "
Flucht in Ketten", literally "escape in chains") her favorite movie (and she also thought Sidney an extremely handsome man). Before I ever saw it for the first time on TV, she had told me a the story a couple of times and I had this vivid imagination what it would be like. The movie, when I finally got to see it on TV, didn't disappoint.