Gospel of Q
The German researchers who pioneered in this work called this lost document "Quelle" which means "source". This is usually abbreviated as "Q" as in the "Gospel of Q."
The Gospel of Q remains a hypothetical document. No intact copy has ever been found. No reference to the document in early Christian writings has survived. Its existence is inferred from an analysis of the text of Matthew and Luke.
Much of the content of Matthew and Luke were derived from the Gospel of Mark. But there were also many passages which appear to have come from Q.
Many theologians and religious historians believe that Q's text can be reconstructed by analyzing passages that Matthew and Luke have in common.
If the Gospel of Q exists, it might best be regarded as a reconstructed Gospel. Many believe that it was written much earlier than the four canonical gospels in the Christian Scriptures (New Testament – in chronological order: Mark, Matthew, Luke and John. It may have been the first of the 40 or so Gospels that were written and used by the early Christian movements.