The New Testament presents three ways in which nets are used, and the use of them determines totally different results. At least four of the twelve disciples of Jesus were fishermen: Simon Peter, Andrew, James, and John (Matthew 4:18-21; Mark 1:16-19). Others of the twelve (with the exception of Judas) participated at least once (John 21:3-11). One way nets were used was a means to provide a living for one's family. In the first two references above, we see that they were professionals who knew what it took to be successful. They knew that "ground work" had to be done before they could begin fishing (pardon the pun). James and John mended their nets. Apparently Peter and Andrew had prepared earlier, or like he was so apt to do, Peter was a doer and not much of a planner. In Luke 5:2-6, we learn that the work did not end when the fishing was complete; they had to wash their nets.
In Luke and John, it is clear that proper preparation does not guarantee success. It is vitally important that the fishermen know where the fish are "biting." On both of these occasions, they had tried their best to catch fish, but they did not know where to look. In the Luke passage, they had given up but Jesus told them to go back and try again. Apparently their timing had been off. In John, it was not so much the timing of their efforts, but more the location. They had lowered their nets on the wrong side of the boat. (the left, or port side is my guess since the starboard, or right side is always right, LOL).
Another way they were used was by the Lord Who used situations involving the use of nets as evidence of His true identity. In Luke, the result was faith and fear. In John, the result was faith and fellowship. This "use of nets" might be described as a tool for soul winning. Jesus had told them to leave the worldly use of nets and come fish for men (Matthew 4:19; Mark 1:17). Both uses of nets in Scripture have some things in common. Both require preparing. Soul winning requires fishermen who are washed (in the blood), who have their lives mended and are lead by the Spirit to "where the fish are biting."
The third way God uses nets is the final way. After men are finished earning a living, and after they work to win souls to Christ, there is a net that leads to judgment. Matthew 13:1-51 Jesus teaches seven parables which describe the Church Age, the age in which we are now living. The last of the seven describes the collection of souls for God's judgment. Fishermen fish for certain kinds of fish, and having collected those that are desirable, they cast the rest out. So it is that when the angels gather the souls of men, they separate the good (those which are deemed righteous by faith in Christ) from the worthless (those who rejected Christ).
We are to be fishers of men seeking the lost. Proverbs 11:30 teaches that those who win souls are wise. Clean you nets, mend them, and go fishing to where Jesus tells you the fish "are biting."