The first crusade had a greater turnout of crusaders due to the motivation. The thirty thousand European Christian crusaders came from all classes including peasants and knights. Some of the motivations were religious and some were not. But, the most popular motivation was religious.
One of the first motivations was the threat from the newly powerful Muslim Turks, so Urban said “we must attack”and so the crusaders attacked when the empire was weakened and divided after the death of an important Turkish leader in 1092. A second motivation was a threat to the Christian church or clergy from bishop clement who also wanted to be pope. Urban knew if Clement united all of Europe Christians no one would be able to challenge his power, he couldn't let that happen, so he attacked. Other monarchies such as France were looking for land from the holy land to rebuild their monarchies and increase their power. The Christian knights and peasants were motivated because they couldn't fight other Christians. Since it was a sin to fight other Christians, it was redirected to non-Christian enemies which were Muslims in this case. The knights fought because it was their duty. Many of the peasants fought because they could escape their lords who ruled them and serfs could be released from feudal obligations. Peasants and poor people also fought because there was a reward after the crusade. This reward included wealth from the Muslim Turks treasures. With these treasures they could live a better life with wealth. A religious reward was if Christians came to fight they were promised that past sins would be forgotten and if they died in battle they would meet their goal, salvation, which is also known as heaven. The most motivational reasons were religious. One of the most motivating reasons was Jesus’ preachings and death took place in the holy land making it very important to the Christians because their savior was there.
Politically the first crusade could bring the Roman Catholic and Greek Orthodox Church back together after their split in 1054. Both Roman Catholic and Greek Orthodox cared about the holy land so it could be used to unite them once again. But, only Pope Urban saw this as a chance to unite while the pope of the Roman Catholic Church saw this as a chance to get land from Jerusalem for himself. He wasn't interested in uniting, he was interested in land.
The Christians weren't the only ones with motivation. The Muslims also had motivation to fight in this crusade. Their motivation was mostly religious. Jerusalem is also the holy land for the Muslims because they are descendants of Ishmael who was Abraham's son. Abraham created a covenant with God saying that if they worship God he will make them the chosen people and he would lead them to the holy land. So the Muslims still saw themselves as the chosen people because they were descendants of Abraham and Ishmael. So they saw themselves as the rightful owners of that land.
The first crusade was full of motivation which allowed so many crusaders to fight and get something in return for their bravery. Crusaders would yell Thousands of crusaders marched to battle yelling “ It is the will of God, it is the will of God!”