The Scriptures used to "prove" Satan and Jesus were originally equal (I am working from memory here in a hurry)
Ezekiel, where Lucifer (Son of the Morning) was called the Cherub that is covering, who was placed in Eden.
Christ says in Revelation "I am the Bright Morning Star"
In Job at the creation "the Morning starS cried out joyfully."
The argument was that originally Jesus had a companion Morning Star, who was cast out, so by the end of the Bible there is only jesus.
Incidentally - as mentioned above, the WT changed the "Salvation" book interpretation fairly recently, saying the mustard seed and leaven parables showed that true christianity would grow slowly until the time of the end. I remember raising an eyebrow at the time, but failedto take adequate note of the magazine.