Again, the kingdom of heaven is like a net that was thrown into the sea and gathered fish of every kind. When it was full, men drew it ashore and sat down and sorted the good into containers but threw away the bad. So it will be at the close of the age. The angels will come out and separate the evil from the righteous and throw them into the fiery furnace. In that place there will be weeping and gnashing of teeth.
The imagery of a net being cast into water again taps into something that Jesus' listeners were very familiar with. The fishermen daily cast their nets and, after pulling them in, sorted out the fish that were edible from those who were not - fish that did not have fins and scales were not to be eaten and the others thrown away. The picture here is that people, like fish, will one day be judged by spiritual beings who know the difference between those who are righteous and those who are evil.
This is the second time in this chapter that Jesus uses the phrase "In that place there will be weeping and gnashing of teeth." He uses it a total of six times in Matthew's gospel. These words communicate two things to me: weeping communicates sorrow; gnashing of teeth communicates anger (as in Acts 7:34). I see no clear reason for the anger except perhaps an anger that emanates from the evils of pride.
Lead me Lord. Not into temptation but deliver me from evil.