The significance of this story to me is the judgment theme. The fisherman in this parable obviously represents God. The fish that are bad represent people who have sinned far too many times and have caused harm to other people.
They are discarded, which is an allusion to being sent to hell by God for the bad deeds done on earth and not changing their ways. The fish which are good are alluding to humans who are God-fearing, and do good deeds while on earth. These are the people sent to heaven.
This parable teaches us that God, although very forgiving, will make judgments upon people when they are taken from the earth. This parable explains to us through the use of fish what is expected by God for those wishing to enter the kingdom of heaven. The good fish represent God’s ideal person that he wants in heaven.
They do not sin as much as the bad fish and they believe in God. The bad fish represent the people in society who God chooses to send to hell. They make bad decisions in their lifetime, such as choosing to ignore God and turning towards bad influences such as drugs. We learn through this parable what it takes to be perceived as a “good fish” by God as opposed to a bad one.