John Gorka's 1990 song "Christmas Bells," available on the Windham Hill compilation A Winter's Solstice III, is based on the poem of the same name, written on Christmas Day in 1864 by Henry Wadsworth Longfellow and published in February 1865. The poem is available in many Longfellow collections, including Longfellow: Poems and Other Writings
Brought low by the death of his wife and the wounding of his son in the Civil War, Longfellow welcomes the bells of Christmas and their message of peace on earth in the poem, but then despairs that there is no peace on earth: Hate is strong/And mocks the song/Of peace on earth, good-will to men. In the end, the bells win him over:
Then pealed the bells more loud and deep:"God is not dead, nor doth He sleep;The Wrong shall fail,The Right prevail,With peace on earth, good-will to men."
Longfellow's "Christmas Bells" consists of seven stanzas, including some that make specific reference to the Civil War. Gorka uses four of the stanzas in his song, which is just one of several musical arrangements of Longfellow's poem that have been done over the years.
The story behind the writing of the poem is told in the 2009 book I Heard the Bells on Christmas Day by Lloyd & Karmel Newell, and illustrated by Dan Burr.