All quotes from My Enemy is My Guest: Jesus and Violence in Luke, by J.M. Ford.
The Gospel of Luke places the dispute about who is the greatest at the last supper: 22.24-30. This is unlike the other Gospels who place it much earlier [Mark 10.35-45; Mat 20.20-28 as a specific petition from James & John, the sons of “thunder”, Zebedee].
The communion service in Luke is followed by Jesus’ warning to Simon Peter that “Satan has demanded permission to sift [test all of them] like wheat”. But what does this mean?
One of the ways Satan will test them is when they use swords in the eventual confrontation-arrest of Jesus in the garden. What follows is the last teaching Jesus will give them before his resurrection. The promise of the New Covenant to share the coming Messianic/Kingdom of God meal with Jesus again will depend on one’s preparation to start living “a life of humility and service, not of political and military leadership and rivalry …”
Apart from the fact that the disciples expected a violent overthrow of the Gentiles by their promised Jewish Messiah, some had revolutionary/political connections [e.g., “sons of thunder” = the Zebedees; Judas Iscariot = of the sicarii, “dagger-men”, assassins; Simon the Zealot].
“[This means that] members of violent resistance movements are to be numbered with transgressors…”
Thus, the buying of swords was to fulfill the prophecy in Isaiah 53.12 as per Luke 22.22 [as planned/determined; cp. Matt 26.24; Mar 14.21 “just as it is written”]. This teaching is brought to clarity in Jesus’ “words that strongly suggest that violent hostility is supernaturally inspired/evil”:
Luke 22.53: “This is your hour and the power of darkness.”
Matthew 26.52: “If you live by the sword you will die by the sword.”
“Jesus’ teaching at the last supper forms a climax to all his teachings that accompanied meals during his earthly life. It means that sword bearers are classified with transgressors…The account would also imply that bearing arms is demonic…This is a sobering thought. It is a readjustment of values.”