Islam is an Abrahamic, heavenly and monotheistic religion, there is only one god according to Islam and that is God, and Muhammad is the Messenger of God. Islam is the second largest religion in the world, with over 1.9 billion followers or 24.8% of the world's population, known as Muslims. Muslims make up the majority of the population in 49 countries. Islam teaches that God is merciful, omnipotent, one, and has guided humanity through prophets and messengers, scriptures and verses. The primary texts of Islam are the Qur'an - which Muslims view as the literal and infallible word of God - and the normative teachings and examples (Sunnah), which include the hadiths of Muhammad. = That Islam is the complete and comprehensive version of the faith that was revealed many times by prophets including Adam, Abraham, Moses and Jesus. Muslims consider the Holy Qur'an the absolute and final revelation from God. Like the other Abrahamic religions, Islam also has a final judgment in which the righteous are granted heaven and the unrighteous are hell (hell). Religious concepts and practices include the Five Pillars of Islam, which are obligatory worship, and following Islamic law, which touches on nearly every aspect of life and society, from banking to women, morals and the environment. Mecca, Medina and Jerusalem are home to the three holiest sites in Islam.