The 5th verse of the Battle Hymn of the Republic

In the beauty of the lilies Christ was born across the sea

With a glory in his bosom that transfigures you and me

As He died to make men worthy, let us die to make men free

While God is marching on

Often is changed to "As He died to make us worthy, let us live to make men free"

I know what this does (it changes the entire meaning of the verse and is, quite frankly, disrespectful to the thousands of people who died in the Civil War), but I do not know why. I know songs are often changed to remove offensive terms (like "n*****" being changed to "chigger" in Oh Susanna), but I don't see how "let us die to make men free" could be seen as offensive in any sense, other than the sexism not addressed by the change. Can someone enlighten me to the reasoning behind the change, and possibly when it took place?