Baigent has written neither a history book nor a religion book. Rather, he has sounded a warning cry about the manner in which extremists of three faiths have very specific plans to attempt the destruction of the world. Baigent's information is relatively easy to corroborate, but he has "connected the dots" in an attempt to warn everyone else that these people genuinely believe in their lunacy and genuinely intend to carry it out.
The three groups of extremists begin with the Jewish extremists who are determined to expand the state of Israel to its Biblical dimensions, which some (basing their thinking on the book of Joshua) regard as extending into modern-day Iraq. They are also determined to rebuild the temple in Jerusalem, and as a first step they want to demolish the Dome of the Rock, which is merely the third holiest shrine in all of Islam. Baigent records how a rabbi present in 1967, when the Israelis reclaimed Jerusalem, insisted that Moshe Dayan take the opportunity to blow up the Dome of the Rock then and there, and how Dayan courageously refused. But the extremists are determined to destroy it. The only problem: They can't attack the Dome without risking a sinful intrusion on sacred ground, and they lack the means of cleansing themselves of this sin.
Enter the red heifer. A pure red heifer with no more than one black hair is required for the ritual to purify those who would assault the Dome. An evangelical Christian cattle rancher in the American South has been working with Jewish ultra-orthodox rabbis to breed such a red heifer. They have almost succeeded on two occasions. The Christian extremist is helping because Christian extremists believe that the Temple must be rebuilt in Jerusalem in order for the Apocalypse to come and Jesus to return. They expect that this will bring on a global catastrophe, a war that will surpass all past wars, but they don't care; they believe they will be magically raptured up to Heaven before the shooting starts, where they can sip tea with Jesus and watch us sinners getting slaughtered.
The key message of this book is not the details of the thinking of the lunatic fringe. Baigent wrote this book in an effort to shake everyone else out of their slumber. He is trying to warn everyone else that these people are determined to take actions that could easily lead to a global nuclear war. He warns us that they genuinely believe that they will somehow prosper in a global catastrophe, and are determined to bring it on. They are really, truly, as deluded and as dangerous as Charles Manson ever was with his Helter-Skelter plot, but with vastly greater resources in their hands.
Measured against his intent, Baigent has done a good job of making the true situation clear and compelling. He has sounded the warning and done it well.