The history of the development of the world's two largest religions (Islam and Christianity) is always filled with the ups and downs (referring to a book by Hugh Goddard) between harmony and conflict. Among the conflicts was the long experience of the Crusade, which took place approximately 3 centuries. This war has been made by some as precedent to continue and justify the conflict between the two religions at any time. This paper examines in depth the history of the Crusade, looks into the background context, interests and motives of the war that were labeled as the holy war. Many things surprised the author that this conflict conceals a lot of information and facts unknown to today’s generations. The author sees that there is a contestation or race between various interests in the history of the Crusade. The crusade turned out to be nothing more than wars labeled as holy but in fact no more than colossal profane such as violent conflicts involving the followers of other religions. Profaneness here not only means that the crusade was a real event, but it also means its background and motives were profane. The holy labeling was merely mobilization strategies to get support of the followers of the religions. Undeniably, there were sincere motives and religious devotion, but of course there were interests and motives purely temporal (secular). However it must be admitted that the crusade was one of the most successful examples of how religion became a major issue to garner support and warfare. A variety of logical justifications were made such as the places, people and position of the blessed to get support. The author also emphasizes that, the context around the time of the Crusade is important to understand, because the era was so far before our time. There were no massive expulsions of religious followers, no inquisition or seizure of holy land one by the religions. Nevertheless, the author realized, if similar things (read: imposition of will, restrictions of religious freedom) are practiced today, then conflict between followers of the religions will occur again since this will be very easy to justify on behalf of God to conduct acts of violence.