The word “Islam” is Arabic word which means “submission to the will of God”. To be called a Muslim, one has to affirm that God (Allah) who is the Creator of all, is the only one worthy of worship, and Muhammad is a last prophet of God, and the holy book "the Qur'an" is revealed on the Prophet Muhammad(sa) and has been transmitted both through oral recitation and as a written book. In addition, one also has to believe in the Day of Judgment, and the four pillars of Islam which includes: Five daily prayers, Certain amount of obligatory charity (zakat), fasting once in a year in the month of Ramadan (siyam), and performing ritual journey to the house of God in Makkah (hajj).
Beliefs in more details
Islam emphasizes on all three dimensions; jurisprudential, moral and intellectual. The basic message of Islam is to spread love, peace and harmony in human society. Spiritual and moral development of human being, purification of soul and tranquility of heart is a most important aspect and ultimate objective of Islam.
The universal message of the Qur'an is that religion cannot be imposed on anyone, human beings are like family members as all are sons and daughters of Adam (as) and Eve, and whoever kills a someone innocently, is as though he had killed all mankind, and whoever saves a life is as though he or she had saved all mankind, and all good and bed deeds will be manifested in the Day of Judgment in their true face. The good doers will be rewarded and the evil doers will be punished.
Followers of all religion should gather on single focal point that is oneness of God and focus on their commonalities. No one is allowed to use abusive language to the beliefs of the followers of other faith.