Why was the Galilee introduced in the Gospel?
The connection is even more strong if one realizes that "Nazareth" is derived from "Ge-Nezareth", the lake of which is placed just in Galilee.
The Galilee is mentioned as opposed to Judea in John 7:1:
After this, Jesus went around in Galilee. He did not want to go about in Judea because the Jewish leaders there were looking for a way to kill him.
Again in 7:40-43:
On hearing his words, some of the people said, “Surely this man is the Prophet.”
41 Others said, “He is the Messiah.”
Still others asked, “How can the Messiah come from Galilee? 42 Does not Scripture say that the Messiah will come from David’s descendants and from Bethlehem, the town where David lived?” 43 Thus the people were divided because of Jesus. 44 Some wanted to seize him, but no one laid a hand on him.
41 Others said, “He is the Messiah.”
Still others asked, “How can the Messiah come from Galilee? 42 Does not Scripture say that the Messiah will come from David’s descendants and from Bethlehem, the town where David lived?” 43 Thus the people were divided because of Jesus. 44 Some wanted to seize him, but no one laid a hand on him.
And finally in verse 52:
They replied, “Are you from Galilee, too? Look into it, and you will find that a prophet does not come out of Galilee.”
Being John a marcionite gospel, was there some anti-Jewish meaning in a Messiah coming from the Galilee?
Add to this the my previous assumption that the story of the Denial of Peter was inserted in all the Gospels only after the writing of Acts of Apostles (since I can't believe that a Peter could kill Ananias and Sapphira for a betrayal when just himself was the champion of all the betrayers, even more I can't believe that the election of Matthias to replace Judas was decided - sic - by Peter).
Well: just in that story we read a particular accusation moved against the Judaizing Peter in Mark 14:66-72:
While Peter was below in the courtyard, one of the servant girls of the high priest came by. 67 When she saw Peter warming himself, she looked closely at him.
“You also were with that Nazarene, Jesus,” she said.
68 But he denied it. “I don’t know or understand what you’re talking about,” he said, and went out into the entryway.
69 When the servant girl saw him there, she said again to those standing around, “This fellow is one of them.” 70 Again he denied it.
After a little while, those standing near said to Peter, “Surely you are one of them, for you are a Galilean.”
71 He began to call down curses, and he swore to them, “I don’t know this man you’re talking about.”
72 Immediately the rooster crowed the second time. Then Peter remembered the word Jesus had spoken to him: “Before the rooster crows twiceyou will disown me three times.” And he broke down and wept.
“You also were with that Nazarene, Jesus,” she said.
68 But he denied it. “I don’t know or understand what you’re talking about,” he said, and went out into the entryway.
69 When the servant girl saw him there, she said again to those standing around, “This fellow is one of them.” 70 Again he denied it.
After a little while, those standing near said to Peter, “Surely you are one of them, for you are a Galilean.”
71 He began to call down curses, and he swore to them, “I don’t know this man you’re talking about.”
72 Immediately the rooster crowed the second time. Then Peter remembered the word Jesus had spoken to him: “Before the rooster crows twiceyou will disown me three times.” And he broke down and wept.
There is some cruel irony or nemesis in the fact that just the Galilee denied by Peter as place of the his provenance (with Jesus) was precisely the place of the final victory of Jesus on Peter himself:
You will all fall away,” Jesus told them, “for it is written:
“‘I will strike the shepherd,
and the sheep will be scattered.’[d]
28 But after I have risen, I will go ahead of you into Galilee.”
Resuming, we have here a Gentile Christian who is going to denigrate the Judaizer Peter by simply remembering him that not only Jesus came FROM Galilee, but also Jesus will appear as risen TO Galilee.
A Jesus coming from Galilee can't be the davidic Messiah. This point is stressed again and again by the marcionite Fourth Gospel and is finally reiterated by the author of the Denial of Peter in Mark as part of an anti-petrine (=anti-Judaizing) denigration.
But in Mark there is already a Jesus who is NOT the davidic "King of the Jews": he is Barabbas.
And when the accusation is addressed against Peter:
“Surely you are one of them, for you are a Galilean.”
...one can't ignore the seditious popularity of Judas THE GALILEAN, hence the suspicion raised about Peter as a seditious of the same kind in virtue of the his presumed provenance from Galilee. Hence the main trait d'union between "Barabbas" and "Galilee" is not only the anti-davidic and anti-christic meaning connected with both "Barabbas" and "Galilee", but also the seditious feature connected with both "Barabbas" and "Galilee".
My conclusion is that the Galilee stands for the gentile lands where there was an increasing number of Gentile Christians dangerously inclined to reject not only the Torah, but also the same god of the Jews as their supreme god. As adorers of a Jesus Son of Father who was never called the Christ.