If one accepts the dating of some modern scholars, the earliest canonical gospel–the Gospel of Mark–was not written until 70 AD or later.
This means there was a gap of time of about 40 years between the life of Jesus and our earliest Gospel that records his words and deeds.
What happened to the stories of Jesus during this period of time? Since such stories were largely passed down orally, can this process be trusted? Did Christians change the stories along the way? Is it reasonable to think that Christians could have even remembered the details accurately?