What is the need and justification of the Sikh religion?

The advent of Guru Nanak in 1469 came at a time of socio-political necessity. India had fallen on evil days. There was no security of life and property.
Guru Nanak rang the alarm-bell and saved masses from fake religions. Religion then was either by form of ritual or hypocrisy. He released people from the rut of formalism and the parrot-like repetition of scriptures. Guru Nanak challenged the division of men into classes, castes and communities. For him, all men were equally worthy of respect.

Guru Nanak stressed the uniqueness of each individual and wanted him to progress through a process of self-discipline. The discipline was three-fold: physical, moral and spiritual. The physical discipline included acts of service and charity, while leading a householder’s life; the moral discipline included righteous living and rising above selfish desires; the spiritual discipline included the belief in only the One Supreme Being, (the Timeless Almighty) and the exclusion of the Pantheon of gods and goddesses, in whom they had formerly believed.

The Gurus brought a course of discipline to their Sikhs that lasted for a period of nearly 230 years till the creation of the Khalsa SIKH, the ideal man of Tenth Guru.
Guru Nanak opposed political tyranny and subjugation. He raised his voice against Babar’s invasion and the tyrannical deeds perpetrated by his army in India. However, the imprisonment of Guru Nanak and the wonderful way in which he conducted himself and performed the tasks assigned to him in the camp awakened the soul of the the Mughal invader. The Guru emphasised the dignity of the individual and his right to oppose injustice and oppression. His main task, however, was to turn men’s minds to God. Guru Nanak opposed mere ceremony and ritualism as dead wood. True religion is purposeful and exalts conscientious living, and not the tread-mill of ritual.
Other than for Guru Nanak, the lamp of spiritualism would have been extinguished in Asia. Guru Nanak is the Light of the world.