Dead saints" is the terminology of many Protestants who argue against the Communion of Saints. The author used that so that those making that argument would recognize that he was answering that argument.
4. The Bible does not show an example of praying or talking to a departed saint
Elijah and Moses conversed with Jesus Christ at the Transfiguration. That is in the piece, too, but you have to read past the first couple of lines.
1. A small percentage believe departed saints are dead. Most believe that to be absent from the body is to be present with The Lord.
2. Christ - God - performed a miracle to have two Old Testament Jewish believers appear together with him. Not even close to the false practice being taught.