The Guru Granth Sahib is the principle source of scripture and religious teaching for Sikhs. The reverence in which Sikhs hold their holy book is summarised in the title 'Sahib' meaning teacher.

For Sikhs the Guru Granth Sahib contains liberating revelations from God given through a number of religious teachers but primarily by Guru Nanak. Although the Guru Granth Sahib contains teaching by other gurus as well as Muslim and Hindu mystics the sacred writings are not a pastiche of teaching from different sources reflecting the context in which Sikhism developed, but divinely inspired teaching from God who is beyond religious titles or sects, and are a path which must be followed.

The forerunner of the Guru Granth Sahib was the Adi Granth which was compiled by the fifth Guru Arjan in 1604 CE. Sikhs were concerned that the teachings of Guru Nanak could become lost or corrupted so Arjan began to collect the teachings of Nanak and of the other three gurus as well as his own verse. These were written in a script called 'gurumukhi' and the Adi Granth contain writing from other religious teachers, such as the Muslims Kabir and Sheikh Farid, showing the Sikhs willingness to accept the experience of God found in other faiths. Later the tenth guru, Gobind Singh added teaching from his father, the ninth guru Tegh Bahadur and his own poetry, and pronounced there would be no further human gurus and that this new book, the Guru Granth Sahib, would become the final guru.

The respect and reverence with which the Guru Granth Sahib is held can be best seen when visiting a Gurdwara. The holy book is kept wrapped on a bed, in a special room at the highest place in the building. When it is removed from its room to be placed in the worship hall it is carried at head height and placed on a raised platform with only the people reading the Guru Granth Sahib being higher than the book.

On entering the worship hall Sikhs will either bow or prostrate themselves before the holy book and make an offering of either food for the langar or clothes that will be used to protect the Guru Granth Sahib itself. All the time the Guru Granth Sahib is being read a chauri is continually waved over the holy book to prevent dust settling on the pages. It would be considered very disrespectful to sit with one's feet pointing towards the holy book. At the end of worship the Guru Granth Sahib is again carried in procession back to the room where it is kept.

The teachings contained in the Guru Granth Sahib are in metered verse that make them easy to chant or sing and this helps make them more memorable. This tradition goes back to Nanak himself who used verse to make his teaching easier to remember. Specially trained musicians accompany the reading of the Guru Granth Sahib during worship.

For many years Sikhs resisted having the Granth printed but the first copies that were not hand made became available towards the end of the nineteenth century and now several versions are available. Because of its size and the honour shown to the Guru Granth Sahib, Sikhs will not have their own personal copy of their holy book as it would be impractical to keep one at home.

In addition to the Guru Granth Sahib there is another collection of religious and moral teachings by Guru Gobind Singh, called the Dasam Granth, which is used for personal devotions.