Why did Guru Nanak make people think that they are all the same?

Guru Nanak emphasized the oneness of humanity and the equality of all people, regardless of caste, creed, or gender, to challenge societal divisions and promote social justice. He taught that everyone is a part of the same divine creation, advocating for love, compassion, and understanding among individuals. By promoting the idea that all souls are equal in the eyes of God, he aimed to foster unity and harmony within diverse communities. His teachings encourage followers to look beyond superficial differences and recognize their shared humanity.