Were the Gospel accounts corrupted as they were passed on? Was there any way to prevent this happening?

Did the early Christian communities apply Jesus's teaching to the problems they faced or alter the facts to fit their agendas?

The way the Gospel accounts use correct place names shows that they were based on reliable information from first hand testimony.

How big are the differences between the hand-written copies of the Gospels' accounts of Jesus? Do these undermine what we can know about…