For its time, this text was revolutionary. Many, though not all, of its assertions have been supported by recent scholarship and proven by a multitude of evidence. This text should be respected for the many contributions it made to our understanding of the subject of comparative religion.
Kersey Graves's Sixteen Crucified Saviors does not deserve the vitriol that it has suffered. Ironically, this author has been 'crucified' by critics since its publication, most of whom have revealed Christian biases. For an example, we need look no further than one particularly fallacious review of this very edition, right here on Amazon:
'Jeri Nevermind' claims, "Christianity not only did not borrow doctrines from pagan sources, but paganism borrowed from Christianity."
It would certainly be convenient for Christian fundamentalists and literalists were it true that Christianity never borrowed doctrines from pagan sources. However, this simply is not the case.
"Paganism" traditionally refers to religions and spiritual practices of pre-Christian Europe. So, strictly speaking, it would be impossible for pagan religions to borrow from Christianity, since Christianity did not exist yet. Obviously, this reviewer is using the term "paganism" to refer to polytheistic traditions or folk religion worldwide, as seen from a Western or Christian viewpoint. This usage of the term reveals the reviewer's Christian bias.
Later in his review, Jeri asserts that the 'history of religion' field of academia is "outdated."
That simply isn't true. Today, in the U.S. and abroad, many universities and some high schools offer courses on the history of religion as well as on the subject of "comparative religion," which specifically address the issue of cross-cultural influences on various religions, including pagan influence on Christianity.
I can't imagine Jeri would have any quarrel with fields such as "history of art" or "history of language." Such fields endlessly reveal the common sense fact that cultural traditions evolve over time due to influences from neighboring cultures. Are we to accept the biased notion that the Christian religion is the only aspect of culture that is above such influence and variation? Of course not. Every culture has its myths. There are Egyptian myths, Greek myths, and - yes - even Jewish myths.
Admittedly, critics are justified in arguing that Kersey Graves's text is dated and imperfect (as should be expected - it was published in the nineteenth century), but to go so far as to claim that Christianity is somehow absolutely free of influence from any other religion is absurd.
Jeri further claims, "There is now not a single credible scholar anywhere in the world that will argue in favor of this theory," referring to Graves's thesis - that there was pagan influence on Christianity. Actually, the reverse is true. Any scholar who claims that Christianity has somehow remained impervious to influence from all other religions is doing so in direct contradiction to the universal and fundamental precept of the study of culture itself - that culture is relative, evolves, etc. That religious traditions borrow from each other is simply a fact. It is implied in the entire concept of 'culture,' of which religion is an integral part.
In conclusion, Kersey Graves's The World's Sixteen Crucified Saviors is not the most up to date nor the most well cited text on this subject. It is, however, one of the first and one of the most important, historically. If you're new to this subject, the works of Robert M. Price or Acharya S. might better suit you. One particularly good starting point, in my opinion, is D.M. Murdock's Christ in Egypt: The Horus Jesus Connection, which meticulously cites primary sources and credible scholars.