In  Islam, iman means believing that Rasulullah (sall-Allahu Taala alaihi  wa salam) is the Prophet sent by Allahu Taala; knowing to be the truth  and saying with belief that he is the Nabi, the Messenger chosen by  Allahu Taala, believing in brief what he conveyed briefly and in detail  what he conveyed in detail from Allahu Taala, and saying the Kalimat  ash-shahada with the mouth whenever possible. Strong iman is such that,  as we know for certain that fire burns and serpents kill by poisoning  and so try to avoid them, we should believe in Allahu Taala and His  Attributes deeming them great, fully at heart, strive for His approval  (rida), run to His beauty (jamal), escape from His wrath (ghadab) and  torment (adhab), and place iman on the heart firmly like an inscription  on marble.