The Parable of the Net
Once again, the kingdom of heaven is like a net that was let down into the lake and caught all kinds of fish. When it was full, the fishermen pulled it up on the shore. Then they sat down and collected the good fish in baskets, but threw the bad fish away. This is how it will be at the end of the age. Then angels will come and separate the wicked from the righteous and throw them into the fiery furnace, where there will be weeping and gnashing of teeth. -- Matthew 13:47-50
Christ's parables were designed to interest all classes of people. The laborer, the farmer, the shepherd, and the fisherman all enjoyed the divine truth brought down to their level of understanding and interest. In this parable, Christ likens the kingdom of heaven to a fishing net cast into the sea. The net encloses within it many kinds of fish which, when full, are brought to shore, where the good are separated from the bad. This will occur, Christ says, at the end of the age, and the angels will be entrusted to do the separating.
In the parable, the world is represented by the waters of the lake, which abounds with all kinds of fish, representing the good along with the bad of mankind.
The net is the gospel, which catches all sorts of men. Many will be attracted by the gospel, but not all who call "Lord, Lord" will be born again. Jesus said that only those who do the Father's will are going to enter into the kingdom of heaven, and that at the judgment day, there will be many who will argue that they had prophesied, driven out demons, and performed miracles in his name, yet who Jesus will say, "I never knew you." Many will be attracted to the gospel, but not all will accept it.