How to achieve real peace ?

In Bhagavad Gita (BG) Lord Krishna instructs to Arjuna,

BG 2.70: A person who is not disturbed by the incessant flow of desires -- that enter like rivers into the ocean, which is ever being filled but is always still -- can alone achieve peace, and not the man who strives to satisfy such desires.

BG 2.71: A person who has given up all desires for sense gratification, who lives free from desires, who has given up all sense of proprietorship and is devoid of false ego -- he alone can attain real peace.

BG 2.66: One who is not connected with the Supreme [in Krishna consciousness] can have neither transcendental intelligence nor a steady mind, without which there is no possibility of peace. And how can there be any happiness without peace?

BG 5.29 and Svetasvatara Upanishad 6.7

People are anxious to attain peace in the material world. But they do not know the formula for peace, which is explained here. "Men should offer everything to the transcendental service of the Supreme Lord because He is the proprietor of everything."

Isopanishad

Iso 1: Everything animate or inanimate that is within the universe is controlled and owned by the supreme Lord. One should therefore accept only those things necessary for himself, which are set aside as his quota, and one should not accept other things, knowing well to whom they belong.