In discussing a single Gospel account that is unified from the texts of the four Gospels of the New Testament, I have many times heard some version of this statement, which is usually given as an objection to a having merged Gospel: “It is important to have the four different Gospels, because they are like four witnesses,” and then they usually add, “at a traffic accident.”
For a while this made sense, until I thought about it. In the first place, the Gospel story of The Life and Ministry of Jesus Christ is not a “traffic accident” – whatever you mean by that. Could a worse analogy be chosen, besides anything else to do with witnessing a murder, war or other crime?
Why not use a positive, meaningful analogy, like, “Four witnesses to a birth” – as in the birth of Christianity. Or perhaps, “four witnesses at the Coronation of a King”; or “four witnesses at a wedding”, as Jesus is pictured as a Groom, and the Church as His Bride (Revelation 19:7, 21:9). You can pick any nice event that requires witnesses, and it will be better, rather than to think of the four Gospel writers as witnesses at a “traffic accident”.