What  is initially necessary for every person to do is to say the kalimat  at-tawhid and to believe its meaning. The kalimat attawhid is: “La ilaha  illa Allah, Muhammadun Rasulullah,” and it means: “Allahu Taala exists  and is One. Muhammad (alaihisalam) is His Prophet.” To believe this fact  means to “have iman,” and to “become a Muslim.” A person who has iman  is called a ‘Mumin (Believer)’ and a ‘Muslim’. Iman has to be  continuous. Therefore, it is necessary to avoid doing acts that cause  disbelief and using things that symbolize disbelief.