After dead

Is there the world after we are dead ?
Until recent day, I decided there is not. I had thought that the memories in the brain will be deleted when the dead has come, such as computer had broken. I had thought that soul is only the electric signals from cell to cell in the brain.
My wife told me her experience. When her grandfather dead, he appeared in her dream, and walk out to wide blight area. When her grandmother dead, she walk out there where he stand. So, she believes that the heaven is existing.
Now I want to believe it is existing.