Baker doesn't seem to have used any scholarly sources about Wicca or Satanism, and is determined to paint them as sister religions. Right from the beginning his depiction of the witch (the villain in the story) as an environmentalist and feminist just makes me suspicious that the author is mocking environmentalism and feminism. So I automatically can't take him seriously.
In the author's defense, he does warn that his Christian POV might be frustrating to non-Christian readers. However, I am a Christian reader, and I find it frustrating. I don't think it's a Christian POV as much as a narrow minded, unresearched, fear-mongering POV.
When I think about young Christians having debates with young Wiccans based on knowledge of Wicca they might have gotten from this book... well that's just embarrassing.