This isn't exactly true. Humans fear death because they don't truly understand what happens afterward. If you are a Christian however, you don't fear death. Because after you die, you finally get to meet Jesus face to face.
I would run.<------I would be too scared to run, I would just slowly carefully back away. while being as casual about it as possible. make it seem like I was walking down the wrong hallway and had just realised and so I had to retrace my steps or something, like "oh how silly of me"