The last two thirds of chapter twelve describe the person who is dear to God, and the description is almost entirely about disposition. Such a person hates no being, is friendly and compassionate, is free of the sense of mine and of the sense of I, is even in pleasure and pain, is patient, content, self controlled and firm in resolve. They do not agitate the world and are not agitated by it. They are free of elation, envy, fear and anxiety.
The list continues: indifferent to whether things go well, pure, capable, impartial, free of distress, having given up every undertaking; neither rejoicing nor hating nor grieving nor craving; the same to friend and enemy, in honour and dishonour, in cold and heat, in pleasure and pain, free of attachment; unmoved by blame and praise, silent, content with anything, without a fixed home, of steady mind.
What is striking about the passage is what is absent from it. No doctrine is required. No ritual is named. No membership of any group is mentioned. The qualities are all observable in ordinary conduct, and most of them are about how a person is with other people rather than about what happens inside them in private.
That is why the chapter has been so widely used outside its own tradition, and why it is often the first passage handed to someone reading the Gita for the first time. It also sits oddly beside the chapters on caste duty and on the ranking of worshippers, and readers have been noticing the tension for a very long time. The Gita is not a systematic treatise, and chapter twelve is one of the places where that shows most clearly.