In contemporary times, there has been a significant shift from the word Moslem to the word Muslim. It is not a random shift but has a well-connected reason to it. According to the idea stated in the American Heritage Dictionary (1992), the usage of the word Muslim is more common amongst scholars and the people who are English-speaking followers of Islam, while the use of the word Moslem is more preferred in the popular context in journalism.
However, the primary reason for this shift in this usage lies in the Arabic roots of the two words. The word Muslim in Arabic refers to someone who has surrendered one’s life to God, while the term Moslem relates to someone who is evil in any sense. It seems to have been the cause of the shift for many people.