If these parables formed a body, would the parable of the dragnet be the appendix? Seemingly all it does is repeat part of the parable of the weeds. Does this parable contribute anything unique?
I think this parable, while teaching the same truths seen in the parable of the dragnet, does contribute something unique. While there unity among all these parables, they are all parables about the kingdom, there is also diversity and progression; with that being the case why repeat an earlier theme? Also, while there are other parables that build on each other and repeat the same idea, such as the parables of the mustard seed and leaven and the parables of the treasure and the pearl, notice how these follow one another. If the parable of the dragnet is meant to do nothing more than repeat the truths of the parable of the weeds why insert so many other parables in between them?
There are two things that make this parable unique, its emphasis and its context.
Whereas the parable of the weeds stresses the delay between the inauguration of the kingdom in sowing the good seed of salvation and the consummation of the kingdom bringing full salvation and judgment, the parable of the dragnet the emphasizes judgment alone. The parable of the weeds answers the question, “Why if the kingdom has come is there still evil present?” The parable of the dragnet warns of certain judgment. D.A. Carson points out the different emphasis saying, “Whereas the parable of the weeds focuses on the long period of the reign of God during which tares coexist with the wheat and the enemy has large powers, the parable of the net simply describes the situation that exists when the last judgment takes place.” In the parable of the weeds we are told of the state of both the weeds and the wheat at the close of the age (vv.42-43), here we are told only of the state of the bad fish. The first parable is an explanation, this one is a warning.
But it is the context that I think makes this parable most distinct and powerful. I think the word that makes it explode with power is the first one, “again”. Initially I thought of this word as nothing more than connective tissue. I read some great commentators who made much of the “again” in v. 45 as indicating the close connection between the parables of the treasure and pearl. I agree there is a close connection, but was bothered by their ignoring the “again” in v. 47. Then I thought what if the “again” is meant to show the relation of all three parables? I believe it is.
How do they relate? It’s like this, the kingdom of heaven will eternally be for you either treasure or torment. The kingdom brings both salvation and judgment, so it will either be your greatest delight or your greatest fright. All that God is will either be for you to enjoy, or for you to fear. God is holy, infinite, sovereign, incomprehensible, self-sufficient, immutable, omnipotent, omniscient, omnipresent, eternal, righteous, and faithful. Will you know all that God is as your eternal and deepest delight or dread?