Among mainstream Christianity, there is a growing sentiment that endorses Christians taking up weapons for their own defense or the defense of others. Some Christians assert that they are justified in killing in self-defense or in anticipation of a crime, believing society would be safer with a more fully armed citizenry. However, the question remains for Christians: Are we ever justified in intentionally killing another human being, even to protect life or property? God's instruction in the scriptures recognizes only two classifications of killing: accidental and intentional. Self-defense is not listed as a possibility. Accidental death occurs when there is no intent to kill or harm, and no awareness that an action will result in death. Intentional killing, even in response to a threat, is defined as murder under God's law. If a man fires a gun with the foreknowledge that it has the potential to kill, it is considered murder. At the core of this issue is the question of whom we allow to govern us. We can either govern ourselves by deciding when it is permissible to kill, or submit to God's authority and His definition of morality. Human nature often insists on prioritizing self-interest over God's law, leading to a willingness to harm or kill to protect personal interests. Taking another man's life in defense of our own also involves acting as judge, jury, and executioner, presuming authority not granted to us by God. Under the New Covenant, God does not promise complete protection from violence. Faithful Christians may suffer harm or persecution, sometimes as a consequence of their actions, and sometimes as part of God's purpose which may not be immediately discernible. Yet, we have His assurance that all things work together for good for those who love Him. Some view God's prohibition against killing as weak, but true strength lies in abiding by His law and trusting in His will, even when threatened. Our faith in God, rather than in self, determines our actions. If God is sovereign in our lives, we will conduct ourselves according to His law, believing in His ability to accomplish His purpose. Regarding Exodus 22:2-3, which addresses a thief being struck and killed while breaking in, the distinction lies between accidental and intentional killing. In darkness, it is harder to determine the necessary level of force, and the law gives the homeowner the benefit of the doubt, assuming no deliberate intent to kill. However, if the act occurs in daylight with clear judgment, and the killing is intentional, it is considered murder. Jesus Christ teaches that murder begins in the heart with intention, reinforcing that intentional killing, even in defense, is against God's law.

In the context of addressing mass murders, the concept of self-defense emerges as a critical consideration. Historical examples like Dodge City, Kansas, founded in 1872, illustrate this principle. Initially known as the murder capital of the United States, Dodge City was a notoriously wild place. Despite attempts at gun control by prohibiting sidearms in certain city sections, these measures failed. By around 1880, the policy shifted to allow everyone to carry a sidearm anywhere in the city. Consequently, the likelihood of immediate retaliation became a significant deterrent to potential murderers. The Dodge City Sheriff's Department, under famous sheriffs like Wyatt Earp, established swift justice plans, and records show that in 1883, with Earp as mayor, only two murders occurred. This fear of immediate retaliation proved to be a powerful deterrent to committing murder, highlighting that allowing self-defense through carrying arms can impact the incidence of violent crime.

Jesus does not rule out self-defense in a life-threatening situation, as His illustrations in the wider context of Matthew 5 demonstrate. His teachings reveal that He addresses minor, yet irritating and inconvenient, interruptions in daily routines rather than prohibiting protection of life. The general principle is that we must not position ourselves as the angry enemy of those who perpetrate evil against us. He advises removing bitterness from our hearts by doing good instead of retaliating with evil, warning against allowing thoughts to build into hatred-based cases against others. This requires significant humility and patience, often diffusing what could escalate into murderous thoughts in our minds.