What does Luke 5:3 mean?
In Luke 4:43, Jesus says, "I must preach the good news of the kingdom of God to the other towns as well; for I was sent for this purpose." This is sometimes difficult when surrounded by a large crowd more interested in physical healing than spiritual restoration (Mark 3:9–10). To keep teaching to a crowd on the shore of the Sea of Galilee, Jesus climbs into Peter's boat. Sound travels well over water, and the crowd will be able to hear Him better. Peter is nearby, washing his net (Luke 5:2).This is the point at which Luke's account significantly differs from Matthew's and Mark's; the other Gospels don't mention Jesus' time in the boat, either preaching or fishing. Mark does, however, seem to indicate that teaching from a boat becomes a habit for Jesus (Mark 4:1).
Why does Peter agree to take Jesus out? One possible reason is that Peter already knows Jesus. His brother Andrew first met Jesus while listening to John the Baptist on the Jordan River. Soon after, he took Peter back with him. At that time, Jesus gave Simon the nickname Peter, but the Gospels, the book of Acts, and Paul's epistles use the two names interchangeably (John 1:35–42).