How activities in Krishna consciousness can lead one ultimately to the spiritual goal is described here. There are various activities in Krishna consciousness, and all of them will be described in the following verses. But, for the present, just the principle of Krishna consciousness is described. A conditioned soul, entangled in material contamination, is sure to act in the material atmosphere, and yet he has to get out of such an environment. The process by which the conditioned soul can get out of the material atmosphere is Krishna consciousness. For example, a patient who is suffering from a disorder of the bowels due to overindulgence in milk products is cured by another milk product, namely curds. The materially absorbed conditioned soul can be cured by Krishna consciousness as set forth here in the Gita. This process is generally known as yajna, or activities (sacrifices) simply meant for the satisfaction of Vishnu, or Krishna.
This Gitopanishad, Bhagavad-gita, the essence of all the Upanishads, is just like a cow, and Lord Krishna, who is famous as a cowherd boy, is milking this cow. Arjuna is just like a calf, and learned scholars and pure devotees are to drink the nectarean milk of Bhagavad-gita