In early Christianity, there was thing called
the agrapha, sayings attributed to Jesus that are not found - “not-written” - in any of the gospelst, but are instead found in other sources like the other books of the NT, the writings of Church Fathers or extrabiblical early Christian literature.
There were quite a number of
agrapha known to early Christians (I believe there were two or three hundred extracanonical sayings), but scholars believe that only a very small segment of those are really authentic - the rest are simply either variations on sayings that
are in the gospels (for example: “Pray for your enemies, for he who is not against is for you”), misattributed sayings, or flat-out inventions.
The scholar Joachim Jeremias (in his book
Unknown Sayings of Jesus) pared the
agrapha down to twenty-one sayings which he thought “has the same claim to historicity as the sayings in our four Gospels;” out of these twenty-one “historically valuable” quotes, he believed only eleven are
possibly genuine (emphasis on the ‘possibly’; we can’t be 100% sure). In fact, a few scholars looking back think that the actual number of authentic
agrapha are even smaller than Jeremias thought: maybe just around half a dozen. And the thing is: even these
agrapha deemed authentic don’t really add anything important to what we already know about Jesus or His teaching. (Nearly) Everyone basically agrees that the four canonical gospels represents mostly all the meaningful information that the early Christians knew about Jesus.
Some examples of possibly and probably authentic
agrapha:
- “Man, if you know what you are doing, you are blessed. But if you do not know, you are cursed and a transgressor of the law” (said to a man working on the Sabbath)
- “He who is near me is near the fire; he who is far from me is far from the kingdom.”
- “Never be content, except when you look upon your brother in love.”
- “He who is far away today will be near you tomorrow.”
- “Ask for the great things, and the small things will be added to you.”
- “Become approved moneychangers.”
- “No one who has not passed through temptation can obtain the heavenly kingdom.”
- “There shall be schisms and heresies.”
- “As you were found so will you be taken away.”