In 2016, the book The Grand Canyon, Monument to an Ancient Earth: Can Noah's Flood Explain the Grand Canyon? was published by Kregel, a leading evangelical publisher. Written by eight professing Christians and three non-Christians (agnostics), it openly rejects the truth of Genesis regarding the Flood and the age of the earth and presents a seemingly water-tight refutation of the geological evidences cited by young-earth creationist geologists. This critique of the book is particularly warranted because the book has been endorsed by some of the most influential evangelical scholars of our time (including Wayne Grudem and C. John Collins) and has been regularly promoted at the annual meeting of the Evangelical Theological Society. This paper critiques the erroneous historical, philosophical, theological and biblical arguments in the book (leaving the geological claims for creation geologists to address later). The analysis begins with a discussion of the critical difference between experimental (operation) science and historical (origin) science and the role of philosophical assumptions in the interpretation of the geological evidence. Then a brief history of the development of the geological theory of millions of years of earth history and particularly the old-earth interpretation of Grand Canyon is presented. Following this important background information is a revealing investigation of the authorship, purpose, promotion, and funding of the book. The rest of the paper gives a thorough evaluation of the relevant non-geological sections of the book. The conclusion is that the book is deceiving many scholars, pastors, laypeople and students in the church as it attacks the truth and authority of Scripture.