hi! dive in on this section of the FAQ, particularly the first post

• Motivations for the Crusades ... and addendum here Was the first Crusade potentially caused by internal developments rather than external threats?

and a few more posts

• Was piety the principal motivation behind the first crusade?

• Were the crusades an inevitable event, or were they purely the brainchild of Pope Urban?

• I saw this article about the Crusades posted on Facebook. How accurate are the bullet points?

This is a very complex question. One could find as many motivations among the principal actors in the Crusades as one could find principal actors.

I'd say it ultimately comes down to what is meant by Religion. Do we mean the metaphysical and philosophical assertions of scriptures, or do we mean the political institution of the churches and priests? Both could be said to be the essence of Religion, if you obi-wan it.

If it is the first, I would say the question is not answerable in a binary fashion. If it is the second, then I would give an emphatic yes.

However, I imagine this answer doesn't help you very much.

From a debate strategy standpoint, my instinct is to take the No position, and make the argument that it was the institution of the church that was the primary mover, not the scripture, and that the institution is not the true essence of religion. Hopefully, your opponent won't have thought about it this deeply, and their argument will seem superficial. It is also likely that they will point to many of the same justifications for their point, which should neutralize them in your favor of you have the deeper argument.