Biblical Criticism & History Forum - earlywritings.com

The Gospel of Luke relies heavily on the Gospel of Mark but omits everything in Mark that lies between the miracle of feeding the 5000 (Mk 06:35-44, Lk 09:12-17) to Peter’s acknowledgment that Jesus was the Christ (Mk 08:27-33, Lk 09:18-22).

That is, after following much of Mark closely, Luke omits:
1. Jesus walking on the sea of Galilee (Mk 06:45-52, Mt 14:22-33)
2. Healing many at Gennesaret (Mk 06:53-56, Mt 14:34-36)
3. Controversy with Pharisees over eating with unwashed hands (Mk 07:01-13, Mt 15:01-09)
4. Exorcising the daughter of the woman from Tyre/Sidon (Mk 07:24-30, Mt 15:21-28)
5. Healing (with saliva) the deaf-mute in region of Decapolis (Mk 07:31-37)
6. Feeding the 4000 in the wilderness (Mk 08:01-10, Mt 15:32-39)
7. Controversy with Pharisees over a sign and warning of leaven of Pharisees and Herod (Mk 08:11-21, Mt 16:01-12)
8. Healing the blind man (after two attempts) (Mk 08:22-26)

Discussion?

GLuke (at its Proto-Luke stage written by Simon the future bishop of Jerusalem) was the first "take-off" from the Evolving Proto-Gospel.
The above items were added later by someone who accompanied Jesus during that trip to Syro-Phoenicia (Mark 7:24-31). It's a round trip journey.
The later "take-off" was the Proto-Matthew later used in writing GMark and GMatthew.
None of these three gospel writers ever saw the other two Synoptics before or during writing.

Jesus walking on the sea of Galilee (Mk 06:45-52, Mt 14:22-33) = shows Jesus was a spirit and Luke was anti-Marcionite hence it would support the heretical flying Jesus. This would support the idea that the 'Mark' used by Luke was not only Marcionite but specifically understood Jesus to be a spirit.