Equality of mankind

Equality and brotherhood of mankind Since about 1499, the Sikh Gurus have emphasised the concept of the equality of mankind in the sacred verses found in the Sikh holy scripture, . Guru Nanak says in Japji Sahib: "Accept all humans as your equals, and let them be your only sect" (Japji 28), and Guru Gobind Singh tell the world: "manas ki jat sabhe eke paihcanbo - recognise all of mankind as a single caste of humanity". Therefore, Sikhs believe that all human beings are equal. “We are sons and daughters of Waheguru, the Almighty”. Sikhs have to treat all peoples of the world on an equal footing. No gender, racial, social, etc. discrimination is allowed. This is the message of Guru Nanak as taught by the 10 Sikh Masters during the period 1469 to 1708.
Guru Angad stood for a caste-less and class-less society, in which no one was superior to the other and no one, through greed or selfishness, could be allowed to encroach upon the rights of others. In short, he visualized a society in which members lived like a family, helping and supporting one another. He not only preached equality but practised it. The son of a successful trader he came to meet Guru Nanak dressed in fine clothes of silk yet no task was beneath him. Guru Nanak's sons, even in those days, felt entitled and above the work and tasks that Guru Angad gladly undertook. 
To promote the acceptance of human equality, Guru Angad established a community kitchen where all sat together in a row, regardless of caste or status, and ate the same food. So strong was his disregard of caste and status that even the Emperor Humayun (Guru refused to meet with the then deposed Emperor until he had first shared a meal in the Guru ka Langar) to task for thinking himself above sitting and eating 'common food' among 'common men'.
Speaking of the Almighty Guru Angad said in the in bani, Sarang ki Var, “He Himself creates, O Nanak; He establishes the various creatures. How can anyone be called bad?. There is One Lord and Master of all; He watches over all, and assigns all to their tasks. Some have less, and some have more; no one is allowed to leave empty.” – Guru Angad Dev .
Furthermore, the guru stressed the importance of adopting a uniform way of praising God and the utility of a social organization based on equality. He established a holy congregation, or Sangat, where people of different beliefs and varying social status sat together to hear the Master's singing of hymns and to be inspired to lead a noble life. 
The following lines from SGGS explain about the importance of treating every person as an equal: