There is a popular saying in Punjab, India
“Baba Nanak Shah Fakir; Hindu ka Guru, Musalman Ka Pir.”
The great Nanak was a saint for all, hindus and muslims alike.
When the Guru passed away in 1539, the Muslims wanted to bury him while the Hindus wanted to cremate him. The next Guru, Angad Dev placed a white sheet on the Guru’s body. He then instructed both the groups to place flowers on each side. The flowers of the group which would be fresh the next morning would determine whether Guru Nanak was a Hindu or a Muslim.
The next morning the flowers of both Hindus and Muslims were fresh, but the body was missing from under the sheet. Hence the above saying seems to have originated.
He was the universal saint.
This verse from the folklore sums up the philosophy of peace, love and tolerance of the first Guru of the Sikhs (1469-1539), Guru Nanak. He is regarded as one of the apostles promoting universal peace through elimination of communal conflicts; a task which he dedicated himself to, all life.
At the age of around thirty he was in Sultanpur where he is reported to have submerged in ‘Jal Samadhi’ (meditation in the water) in river Bein for three days; in communion with the universal spirit.
When he emerged from the water, he uttered
‘Na koi Hindu na koi Musalman’.
(No one is either Hindu nor is anyone Muslim)
A clear reference to his fundamental philosophy of oneness and unity. That one does not relate or commune with the omniscient infinity on the basis of religion; rather as a non-partisan portion of that eternal spirit.
That is why, the first word of the Mool Mantra (which is the beginning verse of the Guru Granth Sahib) attributable to Guru Nanak is
‘Ek Oangkaar’
This phrase provides the very basis of the creation. That there is only one. That supreme infinity, the omnipotence and omniscience. That nothing else exists except as a part of this universal. Ek Oangkaar unifies not just all humans but the entire creation, the animals, the plants and all which can be seen or is unseen. The ‘Sarguun’ or manifest or the ‘Nirguun’ or unmanifest.
A logical corollary to this unity and connectedness is that if I try to hurt someone or even to hurt and destroy nature, I am in reality hurting myself. That shall reflect upon me sooner or later.
That is oneness, the only super-consciousness. All there is. Of which each is made.
Timeless Mind 