Bhagavad gita is a part of Mahabharata and Atharvaveda is a holy book of Hindu. Lord Krishna answers to Arjuna's questions (common man like us). Basically it answers to five common questions which is called Artha panchakam. They are:
1. Who am I? (Jeevathma Svarupam)
2. Who created me? (Paramathma Svarupam)
3. Why I born? (Virodhi Svarupam)
4. Which is Dharma (good action)? (Upaya Svarupam)
5. What is the use of this birth? (Prapya Svarupam)
1. Who am I? (Jeevathma Svarupam)
I am not my name.
I am not a body.
I am not mind .
I am a soul (Jeevathma)
Properties of soul:
1)No birth/No death,
2)Doesn't undergo any change,
3)Made of knowledge,
4)We can't see,
5)Only if it combined with body it can enjoy the joy and sad,
6)It lies in your heart,
7)Every soul is equal,
8) It is a slave for God.Like your body is slave for your soul, it is doing work for you. Like that you need to work for god.Your brain does not have knowledge, but your soul have knowledge
9) Jeevathma is slave for Paramathma(God) which lies inside Jeevathma. Jeevathma is a body for paramathma.
2. Who created me? (Paramathma Svarupam)
