Guru Nanak the founder of the Sikh religion was born in 1469 to an accountant in the Punjab. Nanak was educated as a boy, learning Sanskrit, Persian, and Arabic, but came to have more interest in religion than education. He was married by the age of twelve, to Sulakhani, who bore him two sons. Despite his father`s efforts to steer him into a bureaucratic or business career, Nanak remained enchanted with his spiritual quest.
Around 1499, while bathing in the river Bein, Nanak had a spiritual experience, which he described as a message from God. After three days of visions, he re-emerged, gave away all of his possessions, and became a traveling preacher. He took his message, "There is neither Hindu nor Muslim," throughout India and the middle East, meeting with Hindu and Muslim religious leaders. His message of fraternity and universalism was well received, and his following grew rapidly.
He eventually settled in Kartarpur, where he and his devotees practiced a daily regimen of bathing, prayer, and communal meals. Among these was Guru Angad, who succeeded him as the second Sikh Guru, in a line of succession that continued until 1708, ending with Guru Gobind Singh.
Guru Nanak`s teachings were recorded in the Adi Granth, which formed the basis of Sikh theology. Among the teachings, a unique synthesis of Hindu and Muslim theology, was the insistence that God, whom he referred to using both Hindu and Muslim honorifics, was a formless, unified being that humans could apprehend directly in a state of divine union. Nanak outlined several means to accomplish this union, including meditation on the name of God, purification, and spiritual purity- achieving spiritual detachment. Nanak stressed that Caste was irrelevant, that only inner purity mattered. He admonished practitioners of idol worship and encouraged charity. One of his most influential teachings was the admonishment to his followers to oppose tyranny and oppression.
The Adi Granth, a Sikh Holy Book, transcribed by Nanak`s disciple Bhai Gurdas, contains nearly a thousand hymns, many of which are sung daily during worship. It is written mainly in Punjabi, a language not considered acceptable by the religious elite of the time, an intentional move by Nanak to underscore his insistence that that God favors no caste.