And when he had ceased speaking, he said to Simon, "Put out into the deep and let down your nets for a catch." And Simon answered, "Master, we toiled all night and took nothing! But at your word I will let down the nets." And when they had done this, they enclosed a great shoal of fish; and as their nets were breaking, they beckoned to their partners in the other boat to come and help them. And they came and filled both the boats, so that they began to sink. But when Simon Peter saw it, he fell down at Jesus' knees, saying, "Depart from me, for I am a sinful man, O Lord." For he was astonished, and all that were with him, at the catch of fish which they had taken; and so also were James and John, sons of Zebedee, who were partners with Simon. And Jesus said to Simon, "Do not be afraid; henceforth you will be catching men." And when they had brought their boats to land, they left everything and followed him.
Luke 5:4–11 (RSV)
"Depart from me, for I am a sinful man, O Lord." St. Peter's thoughts were not of fish but his sin. His mind was a swirl of confusion regarding the overwhelming awareness of who he was before God sent him to his knees.
Whatever he had thought of God before that moment was gone in the reality of the miracle wrought by Jesus. For him, a boat nearly sunk with fish had become a holy place, for Jesus was there.
We are mistaken if we think we will stroll into heaven as if we have a perfect right to be there. St. Peter could not stand the holiness he encountered in a boat knee-deep in fish. The perfection of divine beauty we will see as we enter eternity will overwhelm us.
There we will begin to know confession and repentance. We will experience the burning tears of holy sorrow as the first glow of the Father's glory reaches our eyes. We will see that we have no claim on the Kingdom.
St. John the Divine wrote in his Revelation that God Himself would wipe away our tears. Our complete and final repentance will be our first act of joy and praise in eternity. We will at last fully know as we have been fully known. We will see the true sacrifice for our salvation. The resurrection of our Lord will be in our eyes the sunrise no earthly day could provide.
All of this wondrous majesty, holiness, and glory in which the angels eternally dwell begins with Jesus' answer to St. Peter, "Do not be afraid; henceforth you will be catching men."