Shri Krishna introduced this chapter by saying that he will reveal his true nature to Arjuna, which comprises both knowledge and wisdom. He also said that by knowing this, nothing else will remain to be known. Given the powerful nature of this knowledge, one would hope that everyone would seek this knowledge rather than running after new sources of knowledge every day. But this is not the case. Here, he says that those who seek this knowledge are extremely rare in this world. 

With these two verses (4,5), Shri Krishna has covered everything in the world – subject and object, inert and conscious, experiencer and experienced, building blocks and unifying force. 

There are three entities in existence: 1) Matter, which is perishable. 2) The individual souls who are imperishable. 3) God, who is the controller of both matter and the souls. By meditating upon God, uniting with Him, and becoming more like Him, the soul is free from the world’s illusion.”
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