I felt like this might help our understanding of the poem “And did those feet in ancient time…”. The references made in the poem to particular instruments of war (the bow, arrows, spear, and chariot) were reminiscent of Ephesians 6:10-18, and I can’t help but believe this was the allusion Blake was trying to make in the poem. It’s interesting that the tenets of Christianity are laid out in such a militant fashion when there’s so much talk of the violent aspects of other religions (read: Islam) by politically-minded Christians these days. I wonder how Blake would feel about the religious and political rhetoric in America concerning religions other than Christianity, especially after having read “All Religions are One”. In his own time, Blake was a radical. With the current political discourse in mind, I’d say he’d still be considered one, even centuries later. Blake seems to occupy an ostensibly incomprehensible middle-ground between religious zealot, broad-minded philosopher, and prophetic artist. Can we ever allow such contradictory attributes exist simultaneously in a single individual? Our own prejudices tend to subconsciously categorize both subjects and objects to help ourselves understand the world around us. Blake offers one of those glorious exceptions that, in his defiance of categorization, teaches us a lesson about our own propensity towards judgment.
William Blake and Enlightenment Media 
Thank you for digging out this helpful biblical allusion. I agree that the “armor of God” allusion helps explain the specifically Christian spiritual war (“Mental Fight”) that Blake calls for, as opposed to the material wars of humanity that he opposes and labels as anti-Christian (what would Blake think of the U.S. wars in Iraq and Afghanistan today?). Blake is adopting a prophetic voice in recalling this allusion from Ephesians. However, “And did those feet” also includes an allusion to the Greek classical epic in its references to “Bow,” Arrows,” and “Chariot of fire.” Keep in mind that the accompanying preface to Milton refers to “The Stolen and Perverted Writings of Homor & Ovid.” I’m wondering if in this short poem Blake is trying to restore Greek art to its true Biblical original, as evident in Blake’s comments on the Laocoon. In any case, your reading of this poem should aim at a comprehensive interpretation that explains the dual allusion to the epic war imagery–Greek and Hebrew.