Or?

If one was to see "The Northern Horde" as being Gods army?

Then, 

"just as God will disperse his own army? 

So will the army's of the world gathered against him be dispersed."

(Had it written down, I have no idea where from :-).

The whole point seems to be, one way or another:

"the army's of the world gathered against him (God) will be dispersed"

All depends on how you wanna look at it I guess.

"They will interpret scripture differently than in the past."

The New Mystics.

There's just too many different references to a "northern army" for me to take it as for the simile that was used earlier in this chapter about the locust.