The gurus taught that all people were equala concept that went against the dominant caste system of Hinduism, the major religion of India. Since the death of the last guru, Sikhs have continued to revere their teachings, some of which are recorded in a book of wisdom known as the Guru Granth Sahib. Today, there are approximately 23 million Sikhs in the world, making Sikhism the worlds fifth-largest religion. More than 93 percent of all Sikhs live in or near the Indian subcontinent, while North America is home to the second-largest Sikh communities. The MAJOR WORLD RELIGIONS series provides information about six of the most important religious faiths practiced around the world. More than 75 percent of the world's populationover 5.2 billion peopleobserves the tenets of one of these six religions.