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

In this video, Richard Bauckham considers whether we can know who were the main witnesses behind the Gospel accounts of Jesus's life.

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

This video describes the discovery of the earliest copy of part of John's Gospel, the 'John Rylands Fragment'.

Can we be confident that we have the original text of the Gospels? How does it compare to other ancient documents?