This song was composed by the Baptist minister Robert Lowry in the year 1860, on the eve of “strife” unprecedented in the history of the United States. 
The words were adapted by the folksinger Pete Seeger in the 1960s, a period of turmoil of a different nature. I learned it from the album by Gordon Bok, Ann Muir, and Ed Trickett, Turning toward the Morning (1975). 

How Can I Keep From Singing?
My life flows on in endless song
Above earth’s lamentation;
I hear the real though far-off hymn
That hails a new Creation.
 
Through all the tumult and the strife
I hear the music ringing;
It sounds an echo in my soul,
How can I keep from singing?
 
When tyrants tremble sick with fear
And hear their death knell ringing,
When friends rejoice, both far and near,
How can I keep from singing?
 
In prison cell and dungeon vile
Our thoughts to them are winging;
When friends by shame are undefiled
How can I keep from singing?