If that were the whole of the book, it would not have ended up on the best-seller lists or stirred up controversy. Ehrman did not write the book merely to popularize his subject, but as a result of his journey away from Christianity. In the introduction he explains that his faith was shaken to the core when he realized that Mark (or Jesus himself!) might have made a mistake in Mark 2:25-26: 'He answered, "Have you never read what David did when he and his companions were hungry and in need? In the days of Abiathar the high priest, he entered the house of God and ate the consecrated bread, which is lawful only for priests to eat. And he also gave some to his companions."' (TNIV) The mistake is that the high priest in the story was Ahimelech: 'David answered Ahimelek the priest, "The king sent me on a mission and said to me, 'No one is to know anything about the mission I am sending you on.' As for my men, I have told them to meet me at a certain place. Now then, what do you have on hand? Give me five loaves of bread, or whatever you can find."' (1st Samuel 21:2-3, TNIV) Interestingly, there are no textual variations in these passages, so someone made a mistake somewhere.
The bulk of the book explores variations that have come into various manuscript copies of the New Testament. Ehrman constructs plausible theories for why scribes failed to make perfect copies and even introduced variations for doctrinal purposes. Further, he explains how scholars have approached the variants had reconstructed the originals. The journey has many twists and turns, which might trouble people who assume the Bible has been handed down to us in an idealized process. But once you get used to the idea that people copied the texts, made mistakes and sometimes altered words or inserted whole stories for their own purposes, the history Ehrman presents is fascinating. At the end, I found myself wondering what the big deal was. There aren't nearly as many problem texts as it first appears, and modern techniques have solved most of the problems with some certainty. Only a handful of issues remain, and none of those seem terribly dire to the basic picture of Jesus.
Overall, I'd say this book is not an attack on Christianity in general, but on the inerrancy doctrine. Over and over, Ehrman points out that if scribes made mistakes, we don't know what the New Testament originally said and if we don't know the original words, we can't say they are from God. But then he turns around and says that textual criticism can recover the original for the most part. So what is the problem? As far as I can tell, he seems to think that God ought to have supernaturally preserved his word for all generations and that any mistake is a sign that He does not care about scripture. The fact that we have always had a New Testament that is almost identical to the original is of no solace to someone who demands perfection from God's word.
Here's what Paul has to say on the matter: 'All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that all God's people may be thoroughly equipped for every good work.' (2nd Timothy 3:16-7, TNIV) It strikes me that Paul focuses on the Scripture's utility rather than its perfection. I get the feeling that if confronted with Mark 2:25, Paul would have been surprised but unconcerned with Abiathar being there. Instead, he would have praised the teaching of Jesus that "The Sabbath was made for people, not people for the Sabbath." (Mark 2:27b, TNIV) In the same way, the Bible ought to be a benefit to us and not a stumbling block.
Bart Ehrman should be praised for his dedication to the truth, even when it doesn't provide the maximum support for his position. (Compare his books with those of Richard Dawkins, who seems to think any idea that helps make his case should be passed off as true if possible.) There are a variety of people for whom this work will be very troubling—especially those who believe the Bible ought to be perfect. But I found the evidence lacking that the Bible can not be trusted because of errors either in transmission or in the original. Certainly the work of copying and translating the Bible has been entrusted to human hands. Even the composition of the Bible was the responsibility of imperfect people. From the moment God inspired His word until today, it has been at risk of corruption. Incredibly, Misquoting Jesus can be read as the story of how the text of the Bible managed to survive at great odds. For those of us who place our trust on Him (and not merely on the Bible), this should be no surprise.