This is a great hymn, by a minister of the Presbyterian church in the mid 19th century. Written on the eve of the Civil War, it was inspired by the life and death of his friend, Reverend Tyng, who had been forced to resign from his church due to his strong antislavery views. It's an important reminder that the Christian life is a struggle, and that between the City of God and the City of Man there can be no lasting peace. Check out the great reggae/calypso version by Ms. Carlene Davis of Jamaica.
The song is fairly clearly inspired by the 'armor of God' imagery in Ephesians 6, and the last verse alludes to Christ's letters to the seven churches in Revelation 2-3.
1. Stand up, stand up for Jesus! ye soldiers of the cross;
Lift high His royal banner, it must not suffer loss:
From vict’ry unto vict’ry, His army shall He lead,
Till every foe is vanquished, and Christ is Lord indeed.
2. Stand up, stand up for Jesus! The trumpet call obey:
Forth to the mighty conflict, in this His glorious day;
Ye that are men now serve Him against unnumbered foes;
Let courage rise with danger, and strength to strength oppose.
3. Stand up, stand up for Jesus! Stand in His strength alone,
The arm of flesh will fail you, ye dare not trust your own;
Put on the gospel armor, and watching unto prayer,
Where calls the voice of duty, be never wanting there.
4. Stand up, stand up for Jesus! the strife will not be long;
This day the noise of battle, the next the victor’s song;
To him that overcometh a crown of life shall be;
He with the King of glory shall reign eternally.