“…for we cannot stop speaking what we have seen and heard.” (Acts 4:20)
This statement was the defense Peter and the apostles offered when they were told by the Sadducees not to preach in Jesus’ name. The apostles were
offering a defense based on the Law of Moses–they were merely fulfilling their religious duty by giving their testimony about what they had seen
and heard. After all, bearing witness was a legal function and obeying and keeping the Law included bearing witness when necessary. From the context,
the apostles’ controversial testimony was about Jesus’ resurrection. This was what had the rulers so upset.
There was a further item that concerned the rulers–the apostles had done a significant miracle very publicly, which added weight to their message.
Since no book of the New Testament was available for the first fifteen years of church history, there was heavy reliance on the apostles’ testimony
and on the miracles performed by the apostles and by other Christians (even though God was the real worker of miracles). So, evangelists couldn’t
rely on the New Testament during this period–only miracles and apostolic testimony could be used.
How did the early church keep their stories straight? After all, there were evangelists going out and spreading the word. There must have been some
early church documents that were used that didn’t survive that period. Luke tells us that _many_ had undertaken to write an account about Jesus and his works. Hence, there was likely some controversy and, being Jews, the early church used Jewish legal methods to sift the facts. Likely there were several quasi-legal hearings where the apostles formally gave their testimony and were questioned. Jewish judges would have looked for corroboration to establish facts, just as it is specified in the Law of Moses. And there would have been written records of these proceedings that found their way into church archives and eventually were compiled into some of the gospel accounts of the New Testament. Hence, we can be reasonably certain that the gospel accounts of the New Testament are fundamentally based on the testimony of the apostles.