Sikh teaching opens with a statement of what God is: one, true in name, creator, without fear, without enmity, beyond time, unborn, self-existent. Ik Onkar, the numeral one followed by the word for the divine, stands at the head of the scripture and is the tradition's compressed statement of its central claim. God is beyond form and gender, is not incarnate in any person, and is not to be represented in an image; God is also held to pervade creation and to be knowable within it.
The way to that knowledge is naam simran, the remembrance and repetition of the divine name, in recitation, in the congregational singing of the scripture's hymns, and in the ordinary attention of daily life. The obstacle is haumai, self-centredness, which the tradition treats as the root of everything else that goes wrong.
The ethic is stated in three phrases: remember the name, work honestly for a living, and share the proceeds. Withdrawal from the world is rejected; the householder's life, with its obligations, is where the discipline is practised. Caste as a basis for religious standing is rejected likewise, and the langar, the free kitchen attached to every gurdwara, where all sit together and eat the same food, was instituted as a practical refusal of it.
Authority passed through ten Gurus. Guru Gobind Singh ended the human succession and conferred it on the scripture, which is from that point the Guru Granth Sahib, the Guru in the form of the word. It is not a book about the Guru; it is the Guru, and it is treated accordingly, installed on a throne, attended, ceremonially opened in the morning and closed at night. It contains the compositions of six of the Gurus together with those of a number of earlier devotional poets, among them Kabir, Namdev, Ravidas and Farid, whose inclusion Sikhs read as a statement about where truth may be found.