The Gospels are an understandable exception to what classical historians normally deal with, because classical historians rarely if ever deal with the written records of a highly revered religious figure who had very little contemporary significance to anyone but his followers when he was alive and to his worshippers after his death and where the entire written record comes only from those who worshipped him. Because of this, using the myth growth rates observed in other ancient records as a baseline to say what should be observed in the Gospels is a mistaken approach.
Bart Ehrman writes in Did Jesus Exist? - "Technically, we cannot prove a single thing historically. All we can do is give enough evidence (of kinds I will mention in a moment) to convince enough people (hopefully nearly everyone) about a certain historical claim" (page 38). Historians can say if a source or evidence says somebody rose from the dead and it’s a good source or good evidence. But that does not mean they can conclude the resurrection happened. It is a comment on the evidence - and evidence does not necessarily demand a conclusion. History does not find the evidence that Jesus was alive after the crucifixion satisfactory. I am deliberately being neutral. If Jesus was alive resurrection might be one possible reason for that. But we don't have sensible grounds for simply being able to say he was alive. A historian saying Jesus rose and history says so is going too far and failing to be neutral and impartial.Christianity is not primarily about how to treat others but about believing what God has said be it on history or whatever. There is more history and doctrine in the religion than moral rules. Just as it would be a sin to misrepresent what a historian says so it is a sin to reject history that is given to you by God. The focus in Christianity is "factual" claims not morality.Every historian must regard good sources as good but not perfect sources. He thinks they will have errors some of which will never be discovered. A historian who treats the Bible as infallible and without error is not a historian. The Bible actually is the enemy of history for claiming to have no errors and so is the Koran.Strauss argued that the gospels should be looked at as works of theology. Even if they are history they are not about the history but the religious message. I reject that approach. The gospels are intended to teach religious theological history. They attempt to make history religious and theological. They think God reveals through history. God speaks of himself say through the historical fact of the resurrection of Jesus. But is the resurrection really a historical fact? Strauss had no right to treat the gospels as theology just because they do history badly.Many educated Christians lie that history shows that Jesus rose from the dead. It does not. Strictly speaking it shows that people claimed not that he did but that they believed he did. But back to the Christian notion that the resurrection is as good as fact of history as anything else.