This book is a short but informative look at the Bible and how they point to the author's theory of who the antichrist is and what the end times will be like.
The Pope is identified as the first beast. 666 is the numerological value of the words written on his hat, VICARIUS FILI DEI.
The author maintains that the Sabbath is Saturday, not Sunday and that by failing to observe God's true Sabbath you are failing to acknowledge Him as the one true God. The author claims that you can obey the other nine commandments, but if you are lax on this one Satan has won, because your actions say that it doesn't which god you worship.
Marcussen explains in the next chapter that God's children will wear his seal, loyalty shown by keeping His commandments and His Sabbath, Saturday. The seal is Exodus 20:8-11, the only place in the Bible containing God's name, title, and territory. This seal is to be worn in the heart and in obedience. The children of the antichrist will wear his mark by following the authority of the Catholic church. It doesn't matter if you join the Catholic church or not.
But the beast does not enforce his mark. The image of the beast does. Marcussen winds down his book by pointing out all the signs and Bible verses that point to the President of the United States as the image of the beast. Marcussen points out how our government is already blurring the line between church and state with attempts to enforce more morals in this country and points how some states are already trying to do away with the First Amendment altogether. Marcussen claims that when our government and the Catholic church finally get the people to pass laws enforcing the Catholic teachings, the Armageddon of the Bible will be upon us.