I'm confused. Did Jesus advocate violence and killing, or did he not? According to your cherry-picking of Matthew 10?
Why are you confused?
The OT is full of violence and Revelation isn't peaceful. Its war. Good vs evil.
Jesus says get a sword:
"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". Luke
"And they said, Lord, behold, here are two swords. And he said unto them, It is enough". Luke.
And killing those that are considered as being evil:
"For he is the minister of God to thee for good. But if thou do that which is evil, be afraid; for he beareth not the
sword in vain: for he is the minister of God, a revenger
to execute wrath upon him that doeth evil". Romans.
So you are saying Jesus teaches peace. Do you think Christians killing in the name of Jesus are wrong?
Jesus teaches peace but he also teaches violence. They could be thinking they have to fight to get peace.