For Muslims worldwide there are several fundamental words or notions in Islam that serve to renew a basic belief and knowledge in men who would like to sense the essence of Islam in its core values as a precondition for an understanding of the purpose of this worldly life as well as for a belief in Ākhirah, i.e., the next eternal life to come. Since the word has been at the beginning, the word will be with man as long as he lives in this world. Indeed, the word will be with man at the end of his earthly life as a witness for him or against him when he will be put on a reckoning before his Lord to whom he was in debt for his life in this world. Thus, it is of a great importance for man to comprehend the fundamental words as his guidance, as his dīn, i.e., his debt to his success here in this world and his salvation in the Hereafter. For Muslims, it is easier to live a temporal life if man believes that there is another eternal life; for, the one who believes that he or she has two lives is happier than the one who believes that he or she has only one ephemeral life after which is nothingness.