This latter aspect is most problematic when Stenger strays from the strictly scientific (e.g., what does the scientific evidence show about the validity of intelligent design) to the philosophical (e.g., the question of evil). In these cases, he tends to support his conclusions with rather broad strokes. For example, he writes that if religious experiences were as deeply significant as religionists suggest, "then data would exist that even the most die-hard skeptic could not ignore." Likewise, he asserts there is no independent evidence that "any" biblical prophecy has been fulfilled and there is no "incontrovertible physical data" confirming the events detailed in scripture.
Such an approach does not, however, specifically refute the arguments of theists that as much as we may prefer it otherwise, questions of God's existence are not always going to be the stuff of hard evidence. Stenger is prepared, though, noting that the fact such evidence should have been found produces the high probability necessary to draw a scientific conclusion that the God hypothesis has failed objective and scientific scrutiny. At bottom, though, it ultimately reflects the loggerheads between the two views.
Some may find Stenger's conclusion that "we are just a product of circumstance and chance" disconcerting, if not downright depressing. Apparently cognizant of that, Stenger's last chapter is called "Living in the Godless Universe" and he uses it to flesh out his position that belief in a deity is not a prerequisite to finding meaning, wonder and awe in life and the universe.
God: The Failed Hypothesis has its limitations and flaws. All things considered, though, it is a valuable contribution to a growing list of modern works that raise serious and legitimate questions about the basis of religion and its acceptance and impact in the 21st century.