The very fish of his native lake, then, were subject to this strange holy Man! This was no mortal, thought the fisherman, and he fell at the Master's feet. The same "Fear not" ("Be not afraid") was uttered on like occasions to Isaiah (Isaiah 6:7), to Daniel (Daniel 10:12), and several times during the earthly ministry was said to the disciples, and for the last time the reassuring words were spoken by the Redeemer after the Ascension to his own dear follower, John, who could not bear the sight of the glorious majesty of his risen Lord.
It was not "much" that they left - a couple of small boats and their nets; but it was all they had, even all their living. But this showed their love of Jesus, and their willingness to deny themselves, as "really" as if they had forsaken palaces and gold. All that Jesus asks is that we should leave "all" we have for him; that we should love him "more" than we do whatever friends or property we may possess, and be willing to give them all up when he requires it.
[Excerpt from the Pulpit Commentary & Barnes' Notes on the Bible]
"Do not fear!" Creator Sets Free (Jesus) told him. "From now on your nets will catch two-leggeds."
When they returned to the shore, they left everything and began to walk to road with him.
Luke 5:10-11 FNV