653. As everyone knows, a lamb can only behave like a lamb. A sheep can only behave like a sheep. By the same token, a wolf can only behave like a wolf, and a tiger can only behave like a tiger. If all these animals are put in the same space, surely the wolf will devour the lamb and the tiger will devour the sheep. That is why there are shepherds to guard the flock.

As everyone knows, a spring of sweet water is incapable of issuing bitter water from its source. A good kind of tree is incapable of bearing the fruit of a bad kind of tree. A grapevine cannot poke us the way a thornbush can; a lily cannot scrape us the way a bramble can; a hyacinth cannot pull at our clothes the way a thistle can; and neither can these bad plants do what these good plants do. Therefore we pull all those weeds out of fields, vineyards, and gardens, gather them into piles, and throw them in the fire. A similar thing happens to evil people as they arrive in the spiritual world, according to the Lord's words (Matthew 13:30; John 15:6). The Lord also said to the Jews, "You offspring of vipers! How can you say good things when you yourselves are evil? Good people, from the good treasure of their heart, bring forth good things. Evil people, from the evil treasure of their heart, bring forth evil things" (Matthew 12:34-35).