just a thought, and not a very well informed one either.
From what I understand an awful lot of emphasis is placed on prophecy of endtimes or should I say the coming of God, judgement day, armagedon, dooms day etc etc.....
I think some one mentioned earlier (Southstar I think) that after Christ the Christians basically sat around waiting for the prophecy of end times to come and I guess they were dissapointed and well they are still waiting.
I wonder how much of their beliefs are tied into this Doomsday psychology.
The prophecy of devine salvation that will purge the world of all evil and bring heaven to those who believe.
maybe this is why there can be no thrid testament or book because the only way this could happen is that endtimes have to come. But then if they came why would we need a book.
The only thing that can counter the threat of plague and hex is God himself.
so we have millions of people of varius beliefs awaiting for the big day or night.
The main proposition of the extremist cult is that they are preparing for some date that the cult leader deems as the day of the big event. And when it doesn't heppen they commit "hurry curry"
just so they dont miss the boat.
So the bible is mostly about prophecy, an incredible desire to "meet thy maker"
So maybe another book has become impossible unless written by God himself, in person.
In some ways this limitation on the bible has a benefit, for it binds the believer into not exasperating his postion but into a waiting game.