On account of death of the body, the soul does not die. The soul simply changes another body. That's all." This is the first instruction. Tathā dehāntara-prāptir dhīras tatra na muhyati (BG 2.13). For that reason you cannot kill. It is not that Kṛṣṇa was encouraging killing. No. Duty. When there is fight, there is killing. You cannot avoid it. Just like the soldier. What is the duty of the soldier? Kill as many as possible the enemies. But the same soldier, if he comes back home and kills some of his men or countrymen and he is arrested and in the court, he is ordered to be hanged, and if he pleads that "I am a soldier. In the battlefield I have killed so many persons, and now I have killed one man. Why you are ordering me to be hanged?" What will be the answer of the court? The answer that "You cannot kill on principle. But you can kill on the superior order. You cannot kill by your whims." In the battlefield the commander-in-chief orders, "Yes, you kill and get gold medal." But if you think the, "I have killed so many persons in the battlefield. Here is my enemy. I kill him." No. That you cannot do. That you cannot do. This is the principle.