In the early eighteenth century, there was a war between England and Spain called the War of Jenkins' Ear. In the New Testament, there was almost a conflict called the War of Malchus' Ear, but it was averted because Jesus put the ear back (Luke 22:51).
"Then Simon Peter having a sword drew it, and smote the high priest’s servant, and cut off his right ear. The servant’s name was Malchus. Then said Jesus unto Peter, Put up thy sword into the sheath: the cup which my Father hath given me, shall I not drink it? (John 18:10-11).
It is clear from the scriptural accounts that Peter was lacking in spiritual wisdom . . . but he was not lacking in physical courage. We learn in Luke 22 that the disciples only had two swords (Luke 22:38). Those coming to arrest Jesus were an armed multitude with swords and staves, as it says in a number of places (Mark 14:43). So Peter, in possession of fifty percent of those two swords, saw in the multitude of swords and staves before them a clear opportunity to charge. His subsequent denial of the Lord was not because of a lack of animal courage, which he had plenty of. He just didn't know what was going on.
"When they which were about him saw what would follow, they said unto him, Lord, shall we smite with the sword? (Luke 22:49).
Peter thought it was clearly the time for a battle -- but it wasn't. God was setting a trap for the principalities and powers, and Jesus was the bait (1 Cor. 2:8). To fight the bad guys off would have been completely counterproductive of the plan. Jesus had come to earth to die, and He had come to Jerusalem to die. For the disciples to fight would have been to get underfoot in the worst kind of way.
But the problem was not that they had swords in the apostolic band. The problem was that they did not have a clear grasp of what was going on, and therefore did not know when the use of the sword was appropriate, and when inappropriate. Shortly before the confrontation with those who arrested Jesus, the Lord had said this:
"Then said he unto them, But now, he that hath a purse, let him take it, and likewise his scrip: and he that hath no sword, let him sell his garment, and buy one. For I say unto you, that this that is written must yet be accomplished in me, And he was reckoned among the transgressors: for the things concerning me have an end. And they said, Lord, behold, here are two swords. And he said unto them, It is enough" (Luke 22:36-38).
One pacifist take on this passage is that the disciples were simply being spiritually thick again. "Here are two swords," they said eagerly, and Jesus rolled His eyes and said, "Fine. Okay. Do it your way."
Even though the disciples clearly were being thick here, this explanation for the whole series of events is too neat, too facile. The disciples weren't being thick when Jesus first brought the subject up, when He told them to sell a garment to get a sword. Their eagerness in responding showed that there was something wrong in how they were applying what He was talking about (as would be made plain at His arrest), but what Jesus said initially was not sarcastic at all. His reason for telling them to take purse and scrip, and to make sure to get a sword is found in His reference to Isaiah 53.
"Therefore will I divide him a portion with the great, and he shall divide the spoil with the strong; because he hath poured out his soul unto death: and he was numbered with the transgressors; and he bare the sin of many, and made intercession for the transgressors" (Is. 53:12).
What does this have to do with getting yourself a sword? This passage is very clear that Jesus had to die, and to attempt to prevent this by means of the sword was in effect an attempt to fight off the fulfillment of scriptural prophesy with the sword -- a vain endeavor entirely. But Jesus' death was going to be a conquest nonetheless, and He was going to divide the spoil when He was done. When Jesus defeated the strong man, the devil, He stripped him of his panoply, his armor (Luke 11:22). That means one of the things that Jesus took from the devil through His death and resurrection was the devil's sword.
Another interesting feature of all this is found in what Jesus told Peter to do with his sword after he chopped off the ear of Malchus.
"Then said Jesus unto him, Put up again thy sword into his place: for all they that take the sword shall perish with the sword. Thinkest thou that I cannot now pray to my Father, and he shall presently give me more than twelve legions of angels? But how then shall the scriptures be fulfilled, that thus it must be?" (Matt. 26:52-54).
Jesus told Peter to put the sword away, back in its proper place. In the gospel of John, He tells Peter to put it back in the scabbard. He does not say, interestingly, "Throw that thing away," or "What are you doing with that?" or "Don't you know that we have a zero tolerance policy when it comes to assault weapons like that?" Incidentally, the word for sword here is machaira, and is the same word for the weapon that the civil magistrate bears on God's behalf (Rom. 13:4). The contrast here is not being violent and non-violent, but rather between Scripture fulfilled and Scripture not fulfilled. Peter's problem was not that he was being violent, but rather that he was being violent in order to prevent the fulfillment of prophecy.
In the earlier passage, when Jesus told them to sell a garment to get a sword, recall that the disciples produced two of them on the spot. If Jesus had been the original flower child, and had been preaching love-and-peace-brother for three years, and then this happened, it would be really odd. It would be akin to a couple of lifetime Quakers being able to produce a couple of Saturday night specials at the Society of Friends prayer meeting.
Also, in the Matthew passage, Jesus tells Peter that he ought not to resist, but the reason was not because Jesus didn't have military backup if He had wanted it. He said in that place that He could summon up 60,000 angelic warriors more or less -- He didn't need the disciples' two swords if the intent had been to resist. Jesus already had plenty of backup.
So the problem that Peter and the others had was not that they were prepared to use violence if necessary. Their problem was that they did not understand the circumstances under which it would be necessary, and the circumstances under which it would be opposed to the work of God. They did not have the wisdom of Ecclesiastes.
"To every thing there is a season, and a time to every purpose under the heaven . . . A time to love, and a time to hate; a time of war, and a time of peace" (Ecc. 3:1,8).