What do you get when you cross an angel, a demon, a witch hunter, a sixteenth century prognosticator, the Antichrist, and the Four Horsemen on motorcycles? You get the hilarious end-of-the-world vision of Neil Gaiman and Terry Pratchett known as Good Omens.
Good Omens opens with the birth of the Antichrist in a rural hospital in England. The demon in charge of his arrival, Crowley, thinks that all has gone according to plan when he sends a newborn home with a demonic nanny. His adversary, and friend, the angel Aziraphale, does his level best to convert the boy to the side of good, supplying an angelic gardener to counteract the demonic nanny. What neither of them realizes however, is that the Satanic nurse present at the birth made a mistake, and sent the real Antichrist home with another family. They realize their mistake at the boy's eleventh birthday-the date at which the end of the world was supposed to begin. When they realize their mistake, the search for the real Antichrist (a normal 11 year old named Adam) ensues. As strange things with an eerie resemblance to the Book of Revelations start happening all over the world, the forces of good and evil start gathering for the war between Heaven and Hell that is to come, unless four children, a witch hunter, and the descendant of the only prognosticator to correctly predict the events to come can head off the ineffable plan of the Almighty.
Gaiman and Pratchett do a fine job of skewering the whole idea of good and evil. Their basic premise seems to be that good and evil need each other-that the whole point of being good or being evil is to have the opposite side to fight against. This point of view could be seen as an allegory for all kinds of human institutions-competing religions, political ideologies, classes...In addition, they seem to be making a case for atheism, or at least for the existence of God being irrelevant to the daily lives of humans. As Crowley and Aziraphale discuss towards the end of the book, what was the point of creating the Tree of Knowledge if God didn't expect his creations to eat from it? Why give humans free will and the run of an entire planet if you didn't expect them to make their own way? At one point the ineffable plan is defined as a way for God (a word which is never used for the ultimate creator in the book, by the way) to test his creations to see if they work as he devised them-not in his (or her or its) glory, but the way you would test pilot an airplane after you put it together to make sure it would fly. In the end, humanity doesn't need angels or demons to create moments of transcendent glory or moments of horrific cruelty. We do alright on those scores without divine intervention.