Upon the death of his father, Guru Gobind Singh felt compelled to organize the Sikhs into a community of saint-soldiers. During the spring of 1699, the Guru called his followers for a special gathering. During the day, thousands of people assembled in front of a stage and a tent, out of which emerged the Guru to address the massive audience. With sword in hand, the Guru asked the congregation if anyone would be willing to sacrifice their head for him. Naturally, the audience was stunned by the Guru's request, and many followers began to disperse out of sheer terror. Still, the Guru pressed for one of his followers to give their life for him. Finally, one of the assembled stood, with hands folded, and approached the Guru in full submission. The lone disciple was led into the tent by the Guru. After some time, the Guru emerged with a blood-stained sword and asked for another head. Overcome with shock, the audience could not believe what they were seeing; however, another devoted follower stood and offered his head to the Guru. Eventually, with the same outcome, three more devoted disciples offered their lives to the Guru. After the fifth devotee was led into the tent, to the surprise of the massive audience, the Guru emerged with the five followers fully clothed in the uniform of the Khalsa, or Pure. The Guru's demonstration symbolized a revitalization of the Sikh identity and the definitive evolution of the Sikh community into a community of saint-soldiers. After initiating the five "beloved ones" into the new order of the Khalsa, the Guru knelt before them and requested that they initiate him. In the annals of human history, such a transformation into a distinct and solidified community, culminating in the baptism of the prophet by his followers, remains a unique and defining moment.

Guru Gobind Singh and his Khalsa army were engaged in several battles against the imperialist Mughal army during the Guru's life. Through the course of those turbulent times, the Guru lost his four children and his mother to the cause of righteousness; but nevertheless, the Khalsa stood firm as a distinct and sovereign entity, able to withstand the onslaught of a mighty enemy.

In the face of persecution, the Guru wrote:

When all peaceful means of resolution have failed, it is righteous to draw the sword.

Before his death at the hands of an assailant in 1708, the Guru added the writings of Guru Tegh Bahadur to the Sikh scriptures, thereby giving a final revision to its form. The Guru also declared the lineage of living Gurus finished, and requested his followers to seek spiritual guidance from the Guru Granth Sahib. In essence, the light of Nanak, the first Guru, was to be forever enshrined within the pages of the Guru Granth Sahib.

To illustrate his point that the Guru Granth Sahib was the final Guru of the Sikhs, and as a sign of humility, Guru Gobind Singh did not include his writings, over 1400 pages worth of literature, in the Guru Granth Sahib. A separate volume, called Dasam Granth, features the writings of the tenth Sikh Guru.