Were the Crusades political or religious?

Were the Crusades Political or Religious?

The Middle Ages was a religious age that was dominated by papacy. The Crusades show the religiousness of the Europeans in the Middle Ages, though we question ourselves if that was their only motive: Religion. People fought the Muslims, Seljuk Turks, to regain the Middle East in the name of "crusaders" which means "marked with the cross". This was the beginning of the Europe's waking up to use their growing power to look outside Europe and dominate more lands for religious, economic and political reasons. As many as 600,000 crusaders left Europe and marched overland to Jerusalem to "save" the Holy Land of Christianity despite its many difficulties and danger facing them. So then why would all these many crusaders have left their home, family behind to face the threat of the diseases and most likely death? Would it really only have been the pure faiths of religion in them? Or was there something else beyond religious aspects that the Christians wanted? Were the Crusades political or religious?

Indeed, this is a very controversial topic.

English: Medieval miniature painting of the Siege ...

English: Capture of Jerusalem during the First Cru...

English: Pope Gregory VII

But the Crusades were merely religious for political reasons. It is very difficult to point out where the real reasons lie, since both religion and politics involve in the Crusades. Religion, in this case, was simply a great excuse for the Europeans to crush their enemies, the Muslims, and expand their territories and wealth. In addition, Feudalism, the main system of government based on land ownership and military loyalty and service that dominated most of Europe in the 11th Century, supported the Crusades. Pope Urban promised the crusaders a choice of fiefs of the Muslim lands that they conquered, which was especially important to the second sons of the nobility who couldn't inherit their father's land...