Well According to hindu philosophy brahman is a stage we all reach to if we want to, its not a caste but a stage. We all are shudra's by birth, as we trade with the world and attain knowledge , the trading phase make u vaishya(trader), when u are strong enough u become protector that is Khsatriya and the last stage whn u become a sage and want to take sannyasa.. when u get enlightened and understand what is called as brahma (saravam khalvidam brahmam).. u become brahman. In that stage u treat everyone equal (part of god)
