Final answer:
Pope Urban II saw the Crusades as an opportunity to restore church unity, free Jerusalem, and guard the frontiers of Christianity.
Step-by-step explanation:
Pope Urban II saw the Crusades as a golden opportunity in several ways. Firstly, he saw it as a chance to restore unity to the church by offering help to the Byzantine Empire. Additionally, Urban hoped that freeing Jerusalem from non-Christian rulers would mirror the rallying cries to free the church from aristocratic control. He also wanted to guard the frontiers of Christianity and insisted that Spanish Christians should not go on this pilgrimage because they were needed at home in the struggle against Islam in the Iberian Peninsula.