TL,DR at the bottom
That is in Luke 22:36 "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"
This event is found in all four Gospels:
Matthew 26:51&52 Christ says to Peter in verse 52 "Put up again thy sword into his place; for all they that take up the sword shall perish with the sword"
Mark 14:48 but Mark does not record Christ's response.
Luke 22:50&51 Christ's response in 51 is "Suffer ye thus far"
John 18:10&11Christ's response to Peter here is "Put up thy sword into the sheath: the cup which my Father hath given me, shall I not drink it?"
What I understand from Luke 22:36 is: Christ intends for His people to be able to defend themselves.
What I understand from Matthew 26:52 is: Christ does not intend for His people to instigate violence. He tells Peter to put the sword away, not to give it to another or dispose of it. If Malchus had of grabbed Peter first, I doubt Christ would have had a problem with what Peter did.
What I understand From Luke 22:51 is: Suffer in this context means to endure or allow. "Endure ye thus far", or "Allow ye thus far" Christ means for Peter to allow this (His arrest) to happen and not interfere.
John 18:11 echos both Matthew and Luke "Put you sword away" and His rebuke to Peter is a question: "Peter are you trying to prevent Me from doing what God sent me to do?"
Jesus wants us to defend ourselves
Jesus does not want us to instigate violence
Jesus does not want us to hinder God's plan
This was a part of the argument we used to defend our churches policy of allowing anyone that has a HCP to carry on church property.
What that other church is doing is shameful and un-scriptural.