In plain words
He drew Peter, the chief fisherman among them, close. Make the boat ready; let us go out on the river. Getting into it and setting out some distance, He said, "Cast your net in this place; you will get as many as you need." They got as many fish as they had never seen or heard of on any day of their lives. In their great joy the fishermen embraced Jesus and asked, "Not the secret of men, but the secrets of the fish and of the river: are You the one who has grasped them?" Then the answer He gave them was: "I have resolved to establish the kingdom of Prema. This is the command of our Father. You must stand as its chief pillars." From that day on He went on giving these fishermen many kinds of Vedāntic teaching.
Human life is very sacred. It is very precious. It is something we must take care of. In this very life we must behold God. To waste such divine humanness is not right: this He kept teaching those fishermen. He gave them an example. In a river the current was running with very swift water. In that water even tiny fish float on the top, playing, and pass their lives happily. When an elephant with a huge body is let into that same water, the elephant sinks in the water and loses its life. The fish, small in form, went on keeping its life safe in water running so fast, playing and singing and happy. Though it had so large a body, this elephant could not keep its life in the water. What is the reason for this? For what lives in water, swimming is essential, not size. In the same way, in human life, mere learning, or Vedānta, or Vairāgya, is not the chief thing. For man, who lives in the ocean of saṃsāra, we must master the swimming called the Prema of God, which keeps this life safe. Even without knowing any Vedānta, if we have just this one thing, Prema for God, we can live in perfect safety in this ocean of saṃsāra that is the world. The one who has no faith in God, however great a scholar he may be, however great a name he may have earned, has only outward show; he cannot experience Ānanda in it.
The body is like a bubble of water. For us to live by depending on it is Ajñāna itself. So, if we ask what we must live for: we must nourish this body in order to see the indweller. So the care of the body must be done with the goal fixed on the indweller; caring for the body while forgetting the indweller is complete Ajñāna: this He taught.