I'm paraphrasing, by the way. Shifting the focus to Jerusalem was really important because the Crusades were not primarily military operations. They were pilgrimages. Theologically, Christianity didn't have an idea of a holy war. Like, war might be just, but fighting wasn't something that got you into heaven. But pilgrimage to a holy shrine could help you out on that front, and Urban had the key insight to pitch the Crusade as a pilgrimage with a touch of warring on the side. I do the same thing to my kid every night.