When Paul asked John what his last wish was, he requested if he may speak to the parents of the victims. Paul agreed.
John, what is your last wish?
John showed the parents of the two girls what happened by holding their hand just as how John held Paul's hand to share what he sees.
John Coffey was freed after it was proven that he really was innocent.
After many years, Paul told the story to the woman and invited her to go to the mountain.
Do you want to know why I always go up the mountain?
Because of Paul's old age, he was experiencing many different sicknesses. They were already near John's small house when he experienced a severe heart attack. Since John was also old, he was not as strong as he used to be, so he used up all his powers to revive Paul.
John died for Paul because he granted his wish many years ago which saved him from the death row. He owed him his life, so he repayed him.
Just when I thought he couldn't be any nicer, he gave up his life for me.