Jesus is alive. He has risen from the grave, just as He promised. Many people do not believe this, that He rose from the grave. Even His disciples didn't believe it at first.
What did Jesus do to show a sign that He is truly alive and that they're not seeing a ghost or their own imagination? He did what living people do:
When words can't convince the unbelieving to believe
Luke 24 gives us a wonderful account of how Jesus proved to His disciples that He is alive. He did say that the Christ must suffer and die, but after three days rise again.
Here's how He said it according to Luke 9:22:
"The Son of Man must suffer many things, and be rejected by the elders and chief priests and scribes, and be killed, and be raised the third day."
The disciples, despite walking with Jesus for almost the whole duration of His earthly ministry, heard what He said that time but could not believe it. This is apparent in Luke 24:36-39.
"Now as they said these things, Jesus Himself stood in the midst of them, and said to them, "Peace to you." But they were terrified and frightened, and supposed they had seen a spirit. And He said to them, "Why are you troubled? And why do doubts arise in your hearts? Behold My hands and My feet, that it is I Myself. Handle Me and see, for a spirit does not have flesh and bones as you see I have.""
The Lord Jesus, who cannot lie, told His very disciples that He'll be back from the grave after three days. These people saw Him heal the sick, call the dead back to life, multiply food to feed thousands, and many other miracles. Yet they could not believe that He was alive as He promised.
They were terrified, thinking that He was a ghost. Thankfully, Jesus was and is always good; thus came the fish.
"When He had said this, He showed them His hands and His feet. But while they still did not believe for joy, and marveled, He said to them, "Have you any food here?" So they gave Him a piece of a broiled fish and some honeycomb. And He took it and ate in their presence." (Luke 24:40-43)
Jesus chose to do the simplest of things to show His disciples that He was truly alive. Yes, He showed His wounds to them, but more than just showing them His wounds. He did something they did so many times together during His earthly life: eat.
What Jesus did is not of little importance. That small piece of broiled fish is proof that our hope is alive.