After witnessing the miracle healing of his mother-in-law, Peter returns to his normal routine of fishing. His catch of the day was a bust; Peter caught nothing! So, when Jesus tells Peter to drop his nets back into the water, he responds to Jesus and calls him "Master" -- he was willing to do it out of obligatory obedience. Peter didn't agree with Jesus, but he still obeyed. 

But THEN, Peter's miracle happened. The abundance of fish caught that evening was beyond what two boats could hold. Recognizing the true identity of Jesus, Peter kneels before him and says, "Go away from me, LORD; I am a sinful man." Jesus responds to Peter, saying, "Do not be afraid."

Peter moves from fear based obligation to an obedience powered by LOVE. Peter expects condemnation, but instead he recieves grace from Jesus. Then, Jesus extends the invitation to, "Follow him and catch people." His invitation to Peter gives us an invitation to follow Jesus in our brokenness and that our brokenness actually is a prerequisite for discipleship not a disqualifier.