The Question and Answer section for Bhagavad-Gita is a great resource to ask questions, find answers, and discuss the novel.
Krishna says that wise beings should not grieve for the living or the dead: the same person has died earlier and will die again in the future.
44. What does Bhagavad Gita mean? 45. Which of the following does NOT apply to Arjuna? 46. The Bhagavad Gita is part of a larger work. What is the name of the larger work? 47. What is the significance of Kurukshetra? 48. Which is NOT part of the fundament
Sorry you, have too many questions here. You can submit them one at a time. I'm not an expert on this holy text but I will do my best.
That would be the "soul".