His most well-known book is The God Makers: A Shocking Expose of What the Mormon Church Really Believes, co-authored by Dave Hunt.

Decker was born to a Jewish mother and Dutch father of the Reformed Christian faith (Calvinist) but raised an Episcopalian.

While attending Utah State University, he married a Latter-day Saint student named Phyllis and converted to the LDS Church.

In her affidavit, Phyllis Decker Danielson alleges that "the first ten years Ed and I were married, we moved twenty-six times.

Decker has authored and coauthored, books addressing the inner workings and negative aspects of the LDS religion.