With the globalization of ideas in our contemporary times, a Muslim may find the very fundamentals of Islam disappearing from his/her consciousness at an unprecedented pace. This erosion is further accelerated by the heightened criticisms against Islam, its Sharia, its civility, and the degree of involvement any religion should have in people's lives. These challenges make it a necessity to refresh Muslims' collective memories about the central concepts of Islam; those which every Muslim must know. These concepts represent the difference between Muslims and others; the constants of the faith that will forever stand true irrespective of time and place. This book showcases Islam's essential creed and lifestyle, namely what informs a Muslim's theology, value system, and what he/she observes as halal (lawful) and haram (unlawful).