When you sneeze and someone says bless you what does that mean?

I have heard several reasons and they are:

1) Because a long time ago people thought that when you sneezed, part of your soul was escaping. Or that you were releasing demons.

2) Because a sneeze was the first sign of the plague in the 14th century, when people sneezed it was taken as being that they were sick and probably going to die Hence, %26#039;God Bless You%26#039;, now bless you.

3)%26quot;It comes from the idea that you are sneezing out your soul.%26quot; To say %26quot;God bless%26quot; is, in effect, asking God to restore it.
Of course, most people would probably agree that to believe that the soul escapes your body during a sneeze is irrational.

4)The phrase %26quot;God bless you%26quot; is attributed to Pope Gregory the Great who was said to have first uttered the phrase in the 6th century during a bubonic plague epidemic.
But the earliest citation of the phrase is much earlier and is mentioned in Pliny%26#039;s %26#039;Natural History%26#039; written in AD77 where he writes %26quot;...why is it that we salute a person when he sneezes....%26quot;(so obviously he didn%26#039;t know either)

5) When a person sneezed that their heart stopped beating thus giving the Devil a chance to take their souls. God Bless You was apparently said to ward off the Devil and protect the sneezer from evil. Seems far fetched and it has been years since I read the article that contained this information.

Nowadays, I think we say it because it comes naturally, almost like a tradition. :)