The Quran, the holy scripture of Islam, is the most comprehensive source of reference for humankind to understand the teachings of Islam. Undeniably, understanding the Quran is a principal and an important aspect in the life of an individual Muslim regardless of their differences. In reality, understanding the teaching of the Quran and applying it in life can make a servant of Allah s.w.t succeed in all aspects of his life. In order to ensure accurate and correct application of the teachings of the Quran among Muslims, it is important that their level of understanding is investigated first. This will ensure guidance can be provided accordingly and appropriately. This conceptual paper compiles four levels of understanding the Quran among diverse groups of people, which are Naive, Novice, Intermediate, and Expert.