Bring Him Home
The song is from the musical 'Les Misérables'. Its a long story with a pretty grim plot. Set in the time of the French Revolution, it tells how Jean Valjean is released from prison after a mere 19 years hard labour for stealing a loaf of bread. A Bishop forgives him and he makes a new life under a different identity - setting a good example to all and being a general 'do gooder'.
Much later, he is helping on the barricades and he prays that Marius (young revolutionary and good lad) may live through the carnage which must follow. The song is that prayer.
If you want more, then look it up on the web ... or go and see it, it's still on, after more than 20 years.