Mark Gabriel is the pseudonym for a former professor of Islam and Islamic history at Al-Azhar University in Cairo, Egypt. He provides a very helpful way in which to categorize Muslims:
"The secular Muslims. This is a good description of Muslims all over the world. They believe in the nice parts of Islam, but they reject the call to jihad. They take on the cultural trappings of the message, but they are not living it out completely. These Muslims may be very dedicated to their system of thought, even though it does not represent true Islam. The majority of Muslims around the world –both in the East and in the West—fall into this category."
"The traditional Muslims. There are two types of traditional Muslims…first…those who study Islam, know it and practice it, but they have a stumbling block with the concept of jihad. Some consider jihad to be a spiritual battle, like the Muslim Sufism movement…second…people who know that jihad is fighting non-Muslims, but they do not take action…"
"The fundamentalist Muslims. These are the ones who perpetrate terrorism…Their goal is to practice Islam as Muhammad did. Though we call them radicals, they are practicing true Islam (Islam and Terrorism by Mark Gabriel (Pseudonym), 39)"