The Just War theory
Lesson details
Learning outcome
I can explain the Just War theory, describe different Christian views, and give my opinion on whether a war can ever be justified.
Key learning points
- The Just War theory is a set of conditions which, if met, may suggest a war is justifiable.
- It is a largely Christian theory but has influenced international law on conflict.
- It suggests a war can only be called by a figure of authority, this is supported by Romans 13: 1-7.
- Many people argue that a war can never truly be justified.
- Some will use ethical theories, e.g. situation ethics, alongside the Just War theory, to make case-by-case decisions.
Keywords
Just War theory - a set of ethical principles used to decide whether war is morally acceptable
Situation ethics - an ethical theory that emphasises making moral decisions based on the specific situation, rather than relying on fixed rules
Pacifist - someone who believes that all forms of violence are wrong and therefore refuse to participate in war or any other form of violence
Common misconception
Any war fought by Christians is automatically 'just'.
The Just War theory has strict rules that many wars don’t meet. Some students may think wars like WWI or the Crusades were 'just' because Christians fought in them, without realising conditions like the last resort or proportionality weren’t met.
Teacher tip
When referring to Romans 13:1–7, highlight that some Christians take this as support for legitimate authority in war, while others argue it must be balanced with Jesus’ wider teaching on peace. This helps students see how the same text can lead to different interpretations.
Content guidance
Depiction or discussion of violence or suffering
Depiction or discussion of violence or suffering
Supervision
Adult supervision recommended
Licence
Lesson video
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Prior knowledge starter quiz
5 Questions
Q1.Why might land be a reason for a religious war?
Q2.Matthew 10:34 says that Jesus came not to bring peace, but a .
Q3.What were the Crusades mainly about?
Q4.Why do many humanists reject the Crusades?
Q5.The Crusades were about religion but also about land, power and .
Assessment exit quiz
6 Questions
Q1.What is the Just War theory?
Q2.Just War is a largely theory.
Q3.Which Bible passage supports the role of authorities in war?
Q4.Those who always reject war are called .
Q5.What does combining Just War and situation ethics allow for?
Q6.Which conditions of Just War have often not been met in previous wars that were thought to be just because Christians fought in them?
To help you plan your 11 religious education lesson on: The Just War theory, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 11 religious education lesson on: The Just War theory, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 religious education lessons from the Religion, peace and conflict unit, dive into the full secondary religious education curriculum, or learn more about lesson planning.