The correct answer to this open question is the following.
Despite having a basis in religious and ethnic intolerance, the way in that the Crusades increased cultural interaction between Europe and the Middle East was the following.
Beyond waging war during the Crusades, Europeans started to appeal for goods from Asia, India, and China. Muslim goods and art seemed to like European people and trade relationships started to be more common. The famous Silk Road served to connect European merchants with Asian merchants and the exchange of products and ideas through the Silk Road was an important part of trade history in those years.
They believe in god to certain extents