He introduces the conception of God, and that is a concept, which is the subject matter of the whole of the Gita. You cannot resolve problems of man without bringing into man “God”. As long as you try to avoid God, and try to go round and round, the human problems cannot be resolved. And this is what Arjuna was doing, in his argument there is no reference to God at all, you can see the whole argument.
Sri Krishna introduces the idea of God; there is no argument of Dharma–Adharma. He introduces the concept of God and if you read the whole of the Gita, it is nothing but a discussion on what is God, and God in its entirety: God in his inactive, indestructible aspect; God in his mobile and dynamic aspect; God in his omnipresence; God in man; God in creatures; God as an Avatar; God specially manifested in Vibhutis; and God in all his aspects of creation and maintenance and destruction; God as a destroyer; God having His own design and relationship between God and man, and the necessity of man to rise to that consciousness, so that he becomes that vision of God Himself, and then, seeing the root of action, so that the action of God is directly allowed to manifest in the world.
This is the real argument of Sri Krishna, in which therefore the question of Dharma–Adharma, all these are subsidiary questions, it is only by lifting yourself up to the concept of God, and saying that there is nothing else than God in the world. Therefore, all that counts in the world is God’s design, and God is omnipotent and full of mercy, there is complete compassion, He is Satchitananda, Delight! In His will there is no destruction, there is no cruelty, there is nothing but compassion, and he has to be the instrument of that consciousness, and see that God and see what He is doing. And you simply have to be so irresistible to that will, you don’t need to act, neither Dharma–Adharma, nothing, just allow that action to pass through you and that is all. That is the real answer to your question.
All the Eighteen chapters are given therefore, to the perception of God, and how to achieve that perception of God, that is the whole burden of the Gita. But this is the first “dong” as I said. He lifts up the whole argument by saying that, “You are going round and round, see first of all the basis even of your argument. If you want to have inaction, inaction can be justified only on the ground that you want to attain to the Reality, which is inactive. But that Reality is indestructible, and it is the only Reality, therefore the conclusion is that there is nothing which destroyed, and your whole argument is on destruction.” This is the contradiction that on which Sri Krishna first of all shakes the argument of Arjuna. And then of course He will go further.
Let us go quickly over this argument and see the description of the indestructible Reality. He says: “Never did I not exist, nor did you, nor these kings, nor shall we ever cease to exist in the future.” (II, 12) So, where is the question of destruction?
“Just as an embodied soul attains childhood, youth and old age through the body, so it attains another body after death. Wise man does not grieve at this.” (II, 13) Because the Reality is indestructible!
“O Son of Kunti! The objects that are seen by the senses give rise to pleasure and pain, to heat and cold, they are transient. Therefore, O Bharata! Endure them heroically.” (II, 14) You want to achieve the inactive and indestructible Reality, these are only transitory things, bear them and attain to the indestructible Reality.
“O The Best Among Men! Anyone who is balanced in pleasure and pain and who is not agitated by the senses and the contacts with objects, only such a wise person is fit to attain liberation.” (II, 15) Now the word ‘liberation’ comes here for the first time in the Bhagavad Gita, and that is very important: saḥ amṛtatvāya kalpate, you attain to immortality, or indestructibility, or to liberation.