Sentence:  The great ultimate ends of religion have served as magnificent beacon lights that lured people toward them with an almost irresistible force , mobilizing energies and inducing sacrifices ; for example , the <WSD>Crusades</WSD> , mission efforts , just wars . 
Meaning of the word marked with <WSD> tags:  any of the more or less continuous military expeditions in the 11th to 13th centuries when Christian powers of Europe tried to recapture the Holy Land from the Muslims