In the old testament one of the titles of god was simply known as "the name". When a person says protected the name of god or calling apon the name of god its really more the language of localization. Essentially calling apon the power of god.
There is a really great example of this in the book of exodus where an angel with the name of god within him leads the jews out of Egypt.
God's end plan for humanity is for humans to reconciled to him though a personal relationship with jesus christ. Essentially the old testament being which carried his name within him.
Essentially that is reason why adding three vowels to four constants isnt that big a deal.
Jws have basically reduced christianity to harry potter by saying the magic word jehovah.