Today's reading was Matthew 26, which includes at verse 52 "for all who draw the sword will die by the sword." That is often taken as a pacifistic statement in the 20th and now 21st C, but that is a misreading, imposing back on the text what we want it to say.
A disciple is carrying a sword, this late into Jesus's ministry, and he thinks using it to defend someone else - not himself - is quite all right. Perhaps he is wrong. Even at this late date the disciples did not get a good deal of what Jesus was teaching. However... If pacifism was supposed to be a central part of the master's teaching, you would think he would have mentioned it before this: "We don't do that here." There are other references to his followers carrying swords, and in Luke 22 he tells them they might need to buy one. He doesn't seem to be advocating any particular use, such as attacking evil people or overthrowing the government. We cannot even be certain that they are meant for self-defense against humans at all. It might be for safety against animal attack - though that would not likely be the weapon of choice. He doesn't say; we shouldn't assume.
He had just beaten the moneylenders out of the Temple a few hours earlier.
Look at the words which follow immediately: he could call up twelve legions of angels if this were a physical battle. He is stating, then, that this is not a physical battle, and swords will be useless. In the physical realm one lives or dies by swords, but this is not physical. I think it is fair to extend that Jesus is telling them they should be focused on the spiritual events, both in that moment and going forward. He has certainly often said similar things in describing the Kingdom of God in the last three years, of living according to the more important eternal events than the temporary ones of our day.
He does not tell the Centurion to give up his job, nor urge his followers to give up arms. He does speak about giving up rights to your safety and body and goods for the sake of the gospel, and I think that will naturally lead to people resorting less to self-defense, or not at all.
Not all 1st C Christians were pacifists, and those who were tended to argue that no earthly kingdom was worth doing violence for, an argument similar to the one Jehovah's Witnesses do today.