In "God's Word for Today", David Fry writes:

The disciples had failed in one of life’s most basic tasks — providing food for themselves. But Jesus had a hot breakfast of fish and bread prepared for them on shore. It wasn’t the breakfast, however, that had caused Peter to jump out of the boat and swim to shore, but the very appearance of Jesus. Suddenly, food became an afterthought. The disciples had no doubt who Jesus was. Once again, Jesus had provided for them. Those words, “Come and dine,” must have been sweet to the disciples’ ears, and much more because they came from the Savior.
John told this story for one purpose: to illustrate how futile the disciples’ efforts were without the help of Jesus. We must have Jesus as our constant companion in order to experience true success.

Discussion: Why must we have Jesus as our constant companion in order to experience true success?
Source: Miracles of Jesus: Adult Teacher's Insights, page 42.