One formless God (Ik Onkar)

Sikhs affirm Ik Onkar, One, the opening words of the Guru Granth Sahib and of the Mul Mantar, the foundational creed traditionally composed by Guru Nanak, the faith's first Guru, in the late fifteenth or early sixteenth century. It proclaims a single, formless, eternal creator God, without birth or death, self-existent, beyond fear and enmity, realized by grace through the Guru. The Mul Mantar goes on to describe this God with a string of further attributes, commonly rendered as Truth is the Name, Creator, without fear, without hatred, timeless in form, unborn, self-existent, known by the Guru's grace, a formula repeated at the head of most sections of the scripture and treated as a summary creed of the entire faith. The one God is beyond gender and image and is not incarnate; the divine is known not through idols or avatars but through meditation on the Name (Naam) and through the teaching of the Gurus enshrined in scripture.

Guru Nanak's teaching of divine oneness developed in explicit tension with both the caste-structured ritualism he observed in the Hindu society around him and the exclusivist claims he encountered in Islam, and it grounded the practical institutions, such as the shared community kitchen (langar) open to all regardless of caste or creed, through which Sikh belief in one formless God for all people was given concrete social form from the movement's earliest years.

This affirmation of divine oneness is the first and most fundamental of Sikh beliefs, held by all Sikhs and inscribed at the head of their scripture. Its insistence on a formless, non-incarnate God distinguishes Sikh theology both from the image-worship and avatars found in much of the surrounding Hindu tradition and, in its own idiom and lineage of Gurus, from the different exclusivism of Islamic monotheism, positioning Sikhism as a distinct revelation rather than a synthesis or reform of either. The number one written before the word for God expresses that unity is not merely a doctrine among others but the ground of the entire faith, from which its worship, ethics, and community flow.

The line of ten human Gurus that began with Nanak closed in the early eighteenth century when Guru Gobind Singh, the tenth Guru, declared the scripture itself, the Guru Granth Sahib, to be the eternal and final Guru after him, ending the line of living human Gurus. Because the scripture opens with Ik Onkar and the Mul Mantar, that closing act bound the doctrine of divine oneness permanently to the text Sikhs revere as their living spiritual authority, so that engaging the scripture at all begins, for every reader, with this same affirmation of the one formless God.