Universal Brotherhood is one of the basic principals of Sikhism. According to Sikhism, Universal Brotherhood should be highest aspiration of everyone.
Guru Arjan Dev Ji said we are children of the One God and He is our Teacher.
ਏਕੁ ਪਿਤਾ ਏਕਸ ਕੇ ਹਮ ਬਾਰਿਕ ਤੂ ਮੇਰਾ ਗੁਰ ਹਾਈ
(ਸ੍ਰੀ ਗੁਰੁ ਗ੍ਰੰਥ ਸਾਹਿਬ ਜੀ, ਅੰਗ ੬੧੧)
The One God is our father; we are the children of the One God. You (God) are our Guru.
(Sri Guru Granth Sahib Ji, Ang 611)
This concept is further elaborated by Bhagat Kabir Ji who said that if we all are created bu One God, then who is good or bad. Though these all are different forms but still He is pervading everywhere.
ਅਵਲਿ ਅਲਹ ਨੂਰੁ ਉਪਾਇਆ ਕੁਦਰਤਿ ਕੇ ਸਭ ਬੰਦੇ
ਏਕ ਨੂਰ ਤੇ ਸਭੁ ਜਗੁ ਉਪਜਿਆ ਕਉਨ ਭਲੇ ਕੋ ਮੰਦੇ ੧
ਲੋਗਾ ਭਰਮਿ ਨ ਭੂਲਹੁ ਭਾਈ
ਖਾਲਿਕੁ ਖਲਕ ਖਲਕ ਮਹਿ ਖਾਲਿਕੁ ਪੂਰਿ ਰਹਿਓ ਸ੍ਰਬ ਠਾਂਈ ੧ ਰਹਾਉ
ਮਾਟੀ ਏਕ ਅਨੇਕ ਭਾਂਤਿ ਕਰਿ ਸਾਜੀ ਸਾਜਨਹਾਰੈ
ਨਾ ਕਛੁ ਪੋਚ ਮਾਟੀ ਕੇ ਭਾਂਡੇ ਨਾ ਕਛੁ ਪੋਚ ਕੁੰਭਾਰੈ ੨
(ਸ੍ਰੀ ਗੁਰੂ ਗ੍ਰੰਥ ਸਾਹਿਬ ਜੀ, ਅੰਗ ੧੩੪੯)
First, Allah created the Light; then, by His Creative Power, He made all mortal beings.
From the One Light, the entire universe welled up. So who is good, and who is bad? 1
O people, O Siblings of Destiny, do not wander deluded by doubt.
The Creation is in the Creator, and the Creator is in the Creation, totally pervading and permeating all places. 1Pause
The clay is the same, but the Fashioner has fashioned it in various ways.
There is nothing wrong with the pot of clay - there is nothing wrong with the Potter. 2
(Sri Guru Granth Sahib Ji, Ang 1349)
Following is the message of Humanity from Guru Gobind Singh Ji which describes that whole human race is one.
ਕੋਊ ਭਇਓ ਮੁੰਡੀਆ ਸੰਨਿਆਸੀ ਕੋਊ ਜੋਗੀ ਭਇਓ ਕੋਊ ਬ੍ਰਹਮਚਾਰੀ ਕੋਊ ਜਤੀ ਅਨੁਮਾਨਬੋ
ਹਿੰਦੂ ਤੁਰਕ ਕੋਊ ਰਾਫਜੀ ਇਮਾਮ ਸਾਫੀ ਮਾਨਸ ਕੀ ਜਾਤ ਸਬੈ ਏਕੈ ਪਹਿਚਾਨਬੋ
ਕਰਤਾ ਕਰੀਮ ਸੋਈ ਰਾਜਕ ਰਹੀਮ ਓਈ ਦੂਸਰੋ ਨ ਭੇਦ ਕੋਦੀ ਭੂਲ ਭ੍ਰਮ ਮਾਨਬੋ
ਏਕ ਹੀ ਕੀ ਸੇਵ ਸਭ ਹੀ ਕੋ ਗੁਰਦੇਵ ਏਕ ਏਕ ਹੀ ਸਰੂਪ ਸਬੈ ਏਕੈ ਜੋਤ ਜਾਨਬੋ ੧੫੮੫
ਦੇਹਰਾ ਮਸੀਤ ਸੋਈ ਪੂਜਾ ਔ ਨਿਵਾਜ ਓਈ ਮਾਨਸ ਸਬੈ ਏਕ ਪੈ ਅਨੇਕ ਕੋ ਭਰਮਾਉ ਹੈ
ਦੇਵਤਾ ਅਦੇਵ ਜ੍ਨਛ ਗੰਧ੍ਰਬ ਤੁਰਕ ਹ੍ਨਿਦੂ ਨਿਆਰੇ ਨਿਆਰੇ ਦੇਸਨ ਕੇ ਭੇਸ ਕੋ ਪ੍ਰਭਾਉ ਹੈ
ਏਕੈ ਨੈਨ ਏਕੈ ਕਾਨ ਏਕੈ ਦੇਹ ਏਕੈ ਬਾਨ ਖਾਕ ਬਾਦ ਆਤਸ ਔ ਆਬ ਕੋ ਰਲਾਉ ਹੈ
ਜੈਸੇ ਏਕ ਆਗ ਤੇ ਕਨੂਕਾ ਕੋਟ ਆਗ ਉਠੇ ਨਿਆਰੇ ਨਿਆਰੇ ਹੁਇ ਕੈ ਫੇਰਿ ਆਗ ਮੈ ਮਿਲਾਹਿਂਗੇ
ਜੈਸੇ ਏਕ ਧੂਰ ਤੇ ਅਨੇਕ ਧੂਰ ਪੂਰਤ ਹੈ ਧੂਰ ਕੇ ਕਨੂਕਾ ਫੇਰ ਧੂਰ ਹੀ ਸਮਾਹਿਂਗੇ
ਜੈਸੇ ਏਕ ਨਦ ਤੇ ਤੰਰਗ ਕੋਟ ਉਪਜਤ ਹੈਂ ਪਾਨ ਕੇ ਤੰਰਗ ਸਬੈ ਪਾਨ ਹੀ ਕਹਾਹਿਂਗੇ
ਤੈਸੇ ਬਿਸ ਰੁਪ ਤੇ ਅਭੂਤ ਭੂਤ ਪ੍ਰਗਟ ਹੁਇ ਤਾਹੀ ਤੇ ਉਪਜ ਸਬੈ ਤਾਹੀ ਮੈ ਸਮਾਹਿਂਗੇ ੧੭੮੭
(ਅਕਾਲ ਉਸਤਤ, ਸ੍ਰੀ ਦਸਮ ਗ੍ਰੰਥ ਸਾਹਿਬ ਜੀ)
Someone becomes a Ramanandi Monk, or a Sanyasi (the renouncer); others happen to be yogis and some are assessed to have been Brahmcharis or celibates.
Some are Hindus and others are Muslims. someone is lliifazi (ashiah=renouncer-follower of Ali) and another an Imam-Shafi (Sunni=adherent of the Prophet) but ye recognize all human race as one.
Karta=the Creator (of the Hindus) and Karim=the Beneficent (of the Muslims) is the same Lord; He is the Provider of the Livelihood and the Bestower of the Boons. Let none make the error of making distinction between His different names.
They all serve (worship) the One Lord who is the only Enlightener of all. All have been created in His image; ye consider that His is the only light diffused in everyone.(15)(85)
The Temple and the Mosque are the same; there is no difference between them. Neither is there any dissimilarity between the Hindu worship and the Muslim namaz=prayer. The whole human race is the self-same but due to illusion, they appear different.
The demigods, the demons, yakshas (the heavenly dancers), gandharvas (celestial singers), the Muslims and the Hindus all appear dissimilar as they adopt customary dresses of their own countries.
All human beings have the same eyes, the same ears, the same body and the same build. All creation is a blend of the earth, the air, the fire and the water.
As from a big fire, millions of sparks of fire arise, they get scattered and again they merge in the same fire.
As from a heap that consists of myriads of dust particles, those dust bits disperse and arise above and then those dust particles merge in the same dust.
As from a river millions of waves of water are produced and these watery waves merge with water and will still be called as water.
As both the animate (sentient beings) and inanimate (non-sentient objects) are manifested from the Universal Lord. They arise from Him and shall merge again in their primal source.(17)(87)
(Akaal Ustat, Sri Dassam Granth Sahib Ji)
Guru Granth Sahib Ji, the Present Guru of Sikhs, the Holy Scripture of the Sikhs is written by Gurus and various Bhagats, Bhatts and Sikhs as well. These Bhagats were not Sikhs by religion. They were from different religions, castes, places, etc. For example, Bhagat Kabir Ji was a weaver from Banaras, Bhagat Ramanand Ji was a Brahmin from Allahabad, Bhagat Trilochan Ji was a Vaish from Maharashtra, Bhagat Dhanna Ji was a farmer from Rajasthan, Baba Farid Ji a Sufi Muslim from Punjab etc. Bhai Satta Ji and Bhai Balwand Ji were Muslims and their composition is also present in Guru Granth Sahib Ji. So, Guru Granth Sahib Ji itself is an example of Universal Brotherhood.
Guru Nanak Dev Ji started Langar tradition. free kitchen for everyone, where people from all castes and races sit togather and eat food. The main aim behind was unity of people.
The foundation stone of Sri Darbar Sahib, popularly known as Golden Temple, at Amritsar, which is the 'Mecca' of Sikhs was laid not by Guru Sahib but by a Muslim Sufi Saint Hazarat Sain Mian Mir Ji.
The Panj Piare, the Five Beloved Ones of Guru Gobind Singh Ji, were also from different castes and different areas.
That’s why Sikhs in their everyday prayer ask for Sarbat Da Bhala (Well-Being of Human Race). This is how the Sikh Prayer ends
ਨਾਨਕ ਨਾਮ ਚੜ੍ਹਦੀ ਕਲਾ, ਤੇਰੇ ਭਾਣੇ ਸਰਬ੍ਤ ਦਾ ਭਲਾ
(ਅਰਦਾਸ)
God’s glory ever increases; in His Will, Nanak prays for the good of everyone.
(Ardas, Sikh Prayer)
Sikhs work for welfare of whole human race. They believe in Oneness of Humanity. That’s why they pray for everybody. They seek for welfare, peace and prosperity of not only their community but whole human race.
That’s why, Guru Tegh Bahadur Ji, the Ninth Master, sacrificed himself for the sake of Hindus though he was not a Hindu and he was not in any problem. Bhai Kanahya Ji used to give water to everybody in the battlefield irrespective of their race, religion, caste etc. Baba Banda Singh Ji Bahadur also used to equal status to Muslims in his administration and army in his rule. Singhs in the 18th century used to help everyone though they themselves were in great trouble. There was not even a single case of discrimination with any caste or religion during the Sikh Rule of Maharja Ranjeet Singh. Nor there was any communal riot or racial discrimination within people in his rule.
(Translation is done from Sikhi To Max)