Jesus performed many miracles during His time on earth. One tiny example is Jesus feeding more than 5,000 people. We actually have eyewitness testimony in the books of Matthew, Mark, Luke and John corroborating this miracle.
“When it was evening, the disciples came to Him and said, "This place is desolate and the hour is already late; so send the crowds away, that they may go into the villages and buy food for themselves."
But Jesus said to them, "They do not need to go away; you give them something to eat!"
They said to Him, "We have here only five loaves and two fish."
And He said, "Bring them here to Me."
Ordering the people to sit down on the grass, He took the five loaves and the two fish, and looking up toward heaven, He blessed the food, and breaking the loaves He gave them to the disciples, and the disciples gave them to the crowds,
and they all ate and were satisfied. They picked up what was left over of the broken pieces, twelve full baskets.
There were about five thousand men who ate, besides women and children.”
In 2 Peter 1:16 he says, “For we did not follow cleverly devised tales when we made known to you the power and coming of our Lord Jesus Christ, but we were eyewitnesses of His majesty.”
Peter was an apostle who led a very different life after he witnessed Jesus after the resurrection.
I say this because prior to Jesus dying Peter had denied knowing Him to avoid persecution. Also when Jesus died the apostles were scared and scattered. They went back doing what they had been doing before they met Christ. They thought all was lost after Christ died without realizing He would rise from the dead in 3 days.
After Jesus was raised from the dead we see Peter and all the other apostles living very different and changed lives. The apostles had seen the risen Christ. Christ would go on to spend time with them after his resurrection. Most of the apostles would go on to die for their faith in Christ. What changed them? The risen Christ did!