Please let me know your thoughts!
On your first question, I am going to go with the simple and obvious answer, which is that Jesus told them about his encounter with Satan. I imagine that he probably told them this story multiple times. That is how we know. There are many questions similar to this. For example, how do we know what the Jewish leaders said to Judas? I would imagine that Nicodemus was there. How do we know what Mary said to Joseph? Luke certainly was not in the room. Presumably because Mary told her son and the other disciples. It is possible, though not proven, that Luke could have interviewed Mary. By the way, in both the Old and the New Testaments we should not assume that we have exact transcripts of conversations or of sermons. The Sermon on the Mount is surely not a word-for-word transcript of a single sermon. It is one person’s recollection, faithful to the original, under the inspiration of the Holy Spirit, but these are not exact transcripts. In fact, the Sermon on the Mount may be a compilation of important teachings of Jesus from multiple sermons. In modern culture, when we put quotes around a statement, we assume that the words are either exact or very nearly so. Ancient people did not have the same standard we have. So, the idea of “accuracy” in the first century Near East may not be exactly what we would expect today.
Of course, there has been no “objective” account of the Jesus phenomenon. There are no “objective” accounts of any historical event from ancient times at all. Even modern histories are very much affected by personal bias. Ehrman is not telling us anything we do not already know. He is stating the obvious with the purpose of creating doubt. What is necessary is that the New Testament accounts are honest appraisals and accounts of what happened, even if they have an element of bias. For example, either Jesus was betrayed for 30 pieces of silver, or he was not. I believe he was betrayed for exactly 30 pieces of silver, because the context of that passage implies that the number is exact. For example, Peter declared the resurrection of Jesus from the dead at an actual event on the actual Day of Pentecost in the actual temple area in Jerusalem. Either this happened or it did not, and I believe that it happened. Is the account in Acts 2 an exact transcript of the sermon? Probably not! But here is the key point: yes, the resurrection was preached and yes it was in Jerusalem on the Day of Pentecost and yes, many were baptized that day. This is the level of “accuracy” which is required so that we believers can be certain of the New Testament teaching.
Ehrman has a definite agenda and that agenda is to destroy the faith of believers everywhere. That is very clear from what he writes. Why he has that agenda is something that must be asked of the man himself. I would agree that the gospels are at least in some sense “propaganda,” but Ehrman always uses the most prejudiced, negative and inflammatory words he can. To call the gospels “propaganda” is to speak in a highly prejudicial sense. Annual reports from companies are propaganda. CNN and FoxNews reports are propaganda. This does not mean that they contain lies. Ehrman should use a much less inflammatory word than this, but he does not.
I will have to disagree with your statement that “there is no contemporary account of Jesus’ life from the perspective of a pagan.” Josephus, Tacitus, Seutonius and others give their perspective (Josephus, of course, is not a pagan). It is true that there are no witnesses to the resurrection who did not become a Christian and who also wrote about Jesus. I am sure that most of those witnesses went on to become Christians, and we have written accounts from less that one thousandth of one percent of all people who lived back then, so what are the chances that we would have writing from such people? This lack of evidence does nothing to disprove the reliability of the New Testament, but Ehrman is trying to create the false impression that it does create doubt. Well, this is just one more reason I do not trust Ehrman to give good and reasonable perspective.
Here is the bottom line. Either Jesus was crucified and was resurrected or he was not. The evidence is overwhelming in the affirmative for both. Ehrman can try to pick around the edges of the New Testament and he certainly does that, but he simply cannot destroy the basic honesty and reliability of the New Testament on the basic facts, which is that Jesus was an unparalleled miracle-worker, he fulfilled a great number of Old Testament prophecies, he lived an exemplary life, and, as prophesied, he was crucified, buried and raised on the third day. These basic facts are inescapable and they make any highly biased and inflammatory nit-picking by Ehrman irrelevant to the basic question about Jesus Christ.
Would a contemporary account by a non-believing Jew from the first century be helpful? Yes. Actually, we have one–Josephus–but unfortunately he gives us very little about Jesus because that was not his topic. Sure this would be helpful, but a lot of things would be helpful which we do not have. None of this does anything to undercut the basic reliability of the New Testament!!! This statement that such an account would be nice, though true, is irrelevant and it is a smoke screen. By the way, such an account, if it existed, would be “propaganda” as well.
Thanks for sharing your thoughts.