The phrase necessary evil is often used in parallel with sayings such as the ends justify the means, for the greater good, or the lesser of two evils. The expression implies certain immoralities are warranted by the situation. Taken at face value, the expression necessary evil is unbiblical: if something is truly evil, then it is never necessary or morally acceptable. That said, the phrase necessary evil can have some validity, depending on how it is understood. The difference hinges on how one defines the terms involved.
Scripture uses the term evil” in two distinct ways. The most common meaning implies moral wickedness, meaning sin (Matthew 12:35; Judges 3:12; Proverbs 8:13; 3 John 1:11). In common English, this is how the word evil is most often understood. However, Hebrew is a highly contextual language. Old Testament terms referencing moral evil are closely connected to those implying disaster, catastrophe, ugliness, or tragedy (Genesis 50:20; Amos 3:6). Isaiah 31:2, for example, uses both concepts. While modern translations reserve the English word evil for issues of morality, older translations such as Isaiah 45:7 in the King James version have used evil in reference to disaster, resulting in some confusion.
Moral evil is sin: something contrary to the nature of God. Moral evil is never necessary. No matter the situation, God offers a resolution that does not require evil (1 Corinthians 10:13). That which is explicitly forbidden by God’s moral law is neither justified nor excused by any situation. Committing a sin may be “necessary to keep my wealth,” “necessary to keep my power,” or even “necessary to keep my life,” but it is never “necessary in the eyes of God.”
At the same time, actions are themselves defined by circumstances. It is possible for an action to bring ugliness, tragedy, or disaster without being sinful—even if that same action in other circumstances would be a sin. This perspective is not situational ethics, which presumes there are no objective moral laws beyond the ends justifying the means. Rather, it’s an acknowledgement that morality is not defined by words but by our response to God’s will in every moment of life (Romans 14:23; Matthew 5:21–22, 27–28). The opposite of this approach would be legalism, which implies that abstractions and grammar matter more than actual intent (Matthew 15:3–9).
Exodus 20:13 is a relevant biblical example of this difference. Most translations of the Bible render that verse as forbidding “murder.” This is from the Hebrew word ratsach, referring to predatory, unjustified, or premeditated slaughter. This does not mean every instance of one man “killing” another is immoral. Capital punishment (Genesis 9:6), self defense (Exodus 22:2), and legitimate war (Psalm 144:1) are not examples of “murder.” In fact, those actions are sometimes referred to as “necessary evil.” They may be “necessary tragedy,” or “necessary ugliness,” but they are not morally evil—and the difference is in the situations. The moral principle is objective and absolute; the circumstance merely defines if and how that principle applies.
Of course, not all circumstances offer clear-cut lines for making such decisions. Some events in Scripture have been cited to distinguish between justified ugliness and unjustified evil. Hebrew midwives lied to stop infants from being slaughtered (Exodus 1:19–20). For this act, God is said to have “dealt well” with them. Rahab famously lied to protect Israeli spies in Jericho (Joshua 2:1–7), resulting in her rescue from death and her commendation in the New Testament (James 2:25–26). Ehud assassinated the evil king Eglon, leading to an extended peace for Israel (Judges 3:15–30).
Without contradiction, other examples from the Bible show how conventional guidelines cannot be set aside lightly. Saul assumed it would be better to make his own sacrifice, rather than following the rule to wait for Samuel (1 Samuel 13:8–14). That was condemned by God. Uzzah touched the ark of the covenant, arguably to stop it from falling, but in violation of a strict rule (2 Samuel 6:1–7). For that, he was killed by God (1 Chronicles 13:9–12).
A quote encapsulating this dilemma comes from Dietrich Bonhoeffer. Defending his participation in a plot to assassinate Adolph Hitler, Bonhoeffer stated, “What is worse than doing evil is being evil.” Without trying to put words or ideas in Bonhoeffer’s mouth, it would seem his meaning was “What is worse than doing [justified ugliness] is [enabling moral evil].” Of course, even today, Christians are on both sides of such an issue.
The concept of a “necessary evil,” taken literally, is clearly unbiblical. The question of whether circumstances might morally justify actions God would otherwise prohibit—according to His judgment, not ours—is more difficult to untangle. We should not substitute oversimplification for discernment (1 Corinthians 13:11). Scripture says that true moral discernment requires a level of “training” (Hebrews 5:14). And yet, our clear preference ought to be humble and trusting obedience, rather than looking for loopholes or excuses.