Many textual scholars argue that the Pericope de Adultera, the Johannine Comma of I John 5, and Mark 16:9-20 were not in the original texts. I am interested to know how fundamentalists deal with these assertions.
Regarding the Pericope, I have heard several theories: First, that it is indeed authentic, and that the older manuscripts are not as accurate as the later manuscripts. Second, that the account is not authentic, and that we should not preach from it. Third, that the account is not original, but is an authentic account of Christ's actions that was addended to John at a later date, and should therefore be treated as authentic.