And did those feet in ancient time,
Walk upon England’s mountains green:
And was the holy Lamb of God,
On England’s pleasant pastures seen!
And did the Countenance Divine,
Shine forth upon our clouded hills?
And was Jerusalem builded here,
Among these dark Satanic Mills?
Bring me my Bow of burning gold;
Bring me my Arrows of desire:
Bring me my Spear: O clouds unfold:
Bring me my Chariot of fire!
I will not cease from Mental Fight,
Nor Shall my sword sleep in my hand:
Till we have built Jerusalem,
In England’s green & pleasant Land.
I think the popularity of the hymn has to do with its militancy. Militant hymns are striking and stirring in ways that many other hymns are not; they make you want to rise up and do something. And they invoke the sublime, and that is a rare quality in hymns, or, indeed, in any songs whatsoever. Most songs, of course, are better off not even attempting it; but a song that manages to do it without obviously descending into a sort of parody is a rare thing.
Of course, there are hymns that do these things much better than "Jerusalem" does. "The Battle Hymn of the Republic," for instance. But the Battle Hymn, for all its Unitarian provenance, can't be (as Shea notes "Jerusalem" is) a post-Christian hymn; it lacks, for instance, the neo-Pelagian view that progress is something you build by imposing your will on the world. In the Battle Hymn, it is not you who bring progress: it is God's truth that marches on, as inevitable and inexorable as the glory of the morning on the wave, it is He who looses the fateful lightning of His terrible swift sword, against which those who oppose the march of His truth cannot stand. And the only contribution the hymn exhorts people to make to this progress is this, that just as Christ died because that was what it took to make men holy, so we should be willing to die if that's what it takes to make men free, because God is marching on. So much easier to sing that you'll fight ceaselessly to destroy all of the effects of the Industrial Revolution on the basis of a story nobody believes....