User:Kaid100/sandbox
One solution of the Synoptic problem might be that the first gospel, Mark, was taken by other groups such as the Ebionites and Marcionites and heavily revised and added-to to form new gospels which accorded with their own theology. Subsequently, Proto-Orthodox leaders attempted to bring those groups back into Mainstream Christianity rather than than destroying them. To this end, they re-revised both gospels to reflect Proto-Orthodox beliefs, removing some passages, altering a word here-and-there and in some cases adding some new teachings. These new gospels, now known as the Gospels of Matthew and Luke, were then distributed back to the Ebionite and Marcionite groups respectively, with the accompanying message that these new gospels were the in fact original versions of their own gospels, and that any differences were as a result of Ebionite and Marcionite tampering. Ironically of course, both the Ebionites and Marcionites had tampered, but only with the Gospel of Mark, not those of Matthew and Luke, and these new gospels were the result of re-tampering of heretical texts by Proto-Orthodox Christians.
The Gnostic groups, of course, had a wide range of different texts they regarded as scripture, so without a single revered gospel the Proto-Orthodox Christians had to find a different technique to bring them onside. To that end, they created a gospel specifically designed to appeal to Gnostic minds, but without the fuzziness and vagueness of Gnostic texts (which would too easily lead to unorthodox views becomingg premissible). The Gospel of John includes such concepts as the "logos" or "Word", and tends to be spiritual rather than miraculous; things which would tend to appeal to Gnostics.
When the New Testament canon was chosen, each gospel appealed to a different early Christian group while still all conforming to Proto-Orthodox beliefs. The Gospel of Matthew appealed to the pro-Jewish Ebionites. The earlier Gospel of Mark to those who had always been Proto-Orthodox. The Gospel of Luke appealed to anti-Jewish Marcionites, and the Gospel of John to the mystery-loving Gnostics.