What were the goals of the Crusades? What motivated people to go on a crusade besides religious zeal?

The Crusades are probably the greatest symbol of the religious enthusiasm of the age. What were the goals of the Crusades? What motivated people to go on a crusade besides religious zeal? How do we account for the Crusades' general failure? What lasting impact do they have?I need at leastone page double spaced, Times New Roman 12 point font, worksite source.the course uses book: The Western Heritage, Vol. 1, 11th Edition, Kagan, Ozment, and I don't have access to it online.