There are Sikhs by belief and Sikhs by birth. A Sikh’s belief is defined in article one of the Sikh Rahit Maryada (Code of Conduct). However, there are people who would identify themselves as Sikhs but who may not believe in the religion. It was in recognition of this distinction that Sikhs successfully lobbied for paragraph 67 of the 2001 UN Declaration against Racism which takes note of the multiple bases of identity.
Within mainstream Sikhism there is the unifying belief in the Guru Granth Sahib Ji and the Guru Khalsa Panth (Khalsa). Variant groups that exist are the Namdharis and the Nirankaris who believe in a living human Guru. Combined, these groups number in excess of ten thousand.
Within the community there are different attitudes towards the Khalsa. Some regard the Khalsa as an ideal and choose not to join it. Others differ over interpretations of the Sikh Rahit Maryada (Code of Conduct) and follow what they regard as a more traditional line (for example, Akhand Keertanee Jatha and Damdami Taksal) or the interpretations of a holy person (Sant Baba).