If you ever needed motivation for understanding the OT and its proper application, this article serves the purpose. As you read this tragic tale, it is not enough to react emotionally and declare that these pastors are terribly wrong in their application of the OT. You must be able to explain why Exodus 22:18 and Deuteronomy 18:10 are being misapplied in their churches.
I would also encourage you as you prove their exegesis (and application) unbiblical, that you test your evaluation process on your own application of another OT passage say… 2 Chronicles 7:14. This was an interesting exercise in our Old Testament Theology PhD seminar last week.