A commentary in the Navarre Bible has the following regarding this passage. “In these words reported by St. Luke, Jesus Christ reveals his abounding desire to give his life for love of us. He calls his death a baptism, because from it he will arise victorious never to die again. Our Baptism is a submersion in Christ’s death, in which we die to sin and are reborn to the new life of grace: *‘we were buried therefore with him by baptism into death, so that as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life’ Rm 6:4. *Through this new life, we Christians should become set on fire in the same way as Jesus set his disciples on fire.”
Regarding the verse about division it says, “God has come into the world with a message of peace…] and reconciliation …]. By resisting, through sin, the redeeming work of Christ, we become his opponents. Injustice and error lead to division and war. …] Our Lord is forewarning his disciples about the contention and division which will accompany the spread of the Gospel (cf. Lk 6:20-23; Mt 10:24).”
From Vatican II…“Insofar as men are sinners, the threat of war hangs over them and will so continue until the coming of Christ; but insofar as they can vanquish sin by coming together in charity, violence itself will be vanquished.” *Gaudium et spes, *78