Arjuna's collapse comes in an order. The body gives way first (1.29-30), then his sense of what victory is worth (1.31-35), then his reasons (1.36-44), and at last the reasons turn on him (1.45-47).
The closing chapter names the book three ways. It is a dialogue (18.70, 18.74), a secret yoga heard first hand (18.75), and a teaching whose study is an offering (18.70).
The questions shape the Gita: three threads run through them, the call for one decisive answer (2.7, 3.2, 5.1), the marks of the ideal person (2.54, 14.21), and which of two is better (5.1, 12.1).
These verses are spoken inside a vision, to one person, at the edge of a war; the Lord takes away Arjuna's claim to be the author of the outcome and his fear, not his action (11.32-34).
The eight closing verses of chapter 12 draw one person: the centre is mind and intellect offered to the Lord (12.14), and the marks are what that centre looks like in dealing with beings, feelings, events and work (12.13-19).
The promise rests on one whole turning, not on the past: a person of very bad conduct who worships with undivided devotion is to be regarded as righteous, because he has resolved rightly (9.30).
Arjuna asks who knows yoga best. The Lord answers in terms of being joined to Him, not of knowing: the one who fixes the mind on Him, stays steady and has supreme faith is the most united (12.2).
The eight verses describe freedom through action as one ripening: the doer is cleared of grip, ego and craving, the mind grows serene, devotion brings knowledge of the Lord, and the freed person keeps acting (18.49–56).
Offering is the practice that carries the knowledge 'I am not the doer' into the middle of work. The person goes on working; what is handed over is the claim 'this is mine and I want its fruit' (3.30).