“Peacefulness, self-control, austerity, cleanliness, satisfaction, tolerance, simple straightforwardness, devotion to Me, mercy and truthfulness are the natural qualities of the brahmanas.” (Shrimad-Bhagavatam 11.17.16)
If anyone develops the above qualities, they are known as Brahmanas. The advisors to society.
Based on the scriptures, the Brahmanas are not born (caste out from birth), they are created by development of above qualities.
“Peacefulness, self-control, austerity, purity, tolerance, honesty, knowledge, wisdom and religiousness – these are the natural qualities by which the brāhmaṇas work.” (Lord Krishna, Bhagavad-Gita 18.42)
It’s due to ignorance and ego that people have created the caste system in India. People are also foolish to blindly accept someone as a Brahman without seeing proof of the Brahmanical qualities. Based on the Vedic scriptures and common sense, nobody is born as a Brahman. One must have certain qualities developed in order to be called a Brahman. The son of a doctor cannot be called a doctor unless he goes through medical training and becomes qualified as a medical doctor. In a similar way, the son of a Brahmin, cannot be called a Brahmin, unless he develops the qualities of a Brahman (the above qualities).
It should be noted that simply by taking Brahmanical initiation, one does not become a Brahmin. He must exhibit the qualities of a Brahman, as stated in the above 2 verses and others. Never judge a person by the name or clothing or their position, judge a person by their behavior. How they treat others and what they are doing for the benefit of others.