What defines the earliest stage of Sikhism?
Sikhism was founded in Punjab in the 15th century.
Early Sikhism can be defined as the rejection of a discriminatory Hindu caste system, the inclination of worshipers towards a new teacher (Guru Nanak), and Guru Nanak's creation of a new, worship tradition apart from the Hindu faith.
Guru Nanak himself was born into the Hindu religion of the Sant order. The Sants were well known for crafting the most beautiful and exquisite of hymns. The Sants' veneration for poetry and a mystical interpretation of religious faith became part of Guru Nanak's new religious tradition.
The early Sikhs would gather in congregations or sangat; congregational worship was known as kirtan. Sangats were usually accompanied by string musical instruments and leather drums. Each session would also include kathas, interpretations of Guru Nanak's works by various, respected members of the religious community.
During the week, the early Sikhs would arise to the singing of one of Guru Nanak's beautiful hymns and read together from the Sikh scriptures, the Jap Ji. The Jap Ji references Nanak's thoughts on Kartar, the Divine Creator. After the day's labors and in the evenings, the worshipers would invariably read from more of Nanak's compositions and perhaps sing one of his night hymns.
An important new development which has prevailed to the present day is the development of the Sikh communal kitchens or langars. Members of the community would donate produce from their homes and gardens, participate in the preparations of the food, and enjoy the repast in consecrated fellowship. The breaking of bread together constituted both an act of divine worship and service to each other.
Guru Nanak's early legacy was continued by nine more Gurus. Upon the death of the tenth Guru, the Eternal Spirit was transferred to the Sikh Holy Scriptures, the Guru Granth Sahib. Thus, the scriptures became the representation of the eternal and sole Guru.