Can you think of a US President who carried a gun? Most (if not all) have found it completely unnecessary. Why?
Presidents are protected by the best security system and body guards that money can buy — the Secret Service. That protection (if they listen to and follow the instructions of the Secret Service) is far better and more effective than any protection they could provide themselves by carrying their own guns. Besides that, presidents are too busy to have to think about and worry about their own protection. So they trust the Secret Service
(However, Secret Service protection isn’t perfect. Five presidents have been shot while in office. Ronald Reagan was wounded and hospitalized and four others were assassinated — Abraham Lincoln, James Garfield, William McKinley, and John Kennedy.)
There is another group of people who are offered even better body guards than the Secret Service. Christ-followers are offered angels and the Holy Spirit as their body guards. They don’t have to think about and worry about their own protection if they will listen to and follow the Holy Spirit. (God and His are much more powerful and effective than the US Secret Service).
If God’s protection is real (it has saved my life several times and frequently kept me safe on the streets in violent neighborhoods) then we can trust Him. Like American Presidents we don’t need to personally carry arms. However, if God’s protection isn’t real (or isn’t trustworthy) then perhaps it makes sense for Christians to bear arms to protect themselves.