Shared ground
Deuteronomy 20:1–4 treats fear as a real battlefield problem, especially when Israel sees an enemy that looks stronger (horses, chariots, larger numbers). The passage’s main claim is not that Israel will win by superior skill, but that they should not collapse in fear because Yahweh is with them.
The text also ties present courage to remembered deliverance: the God who goes with them is the one who brought them out of Egypt. That memory functions like public evidence of God’s ability and commitment, not as a new battle plan.
A second shared point is the role of speech and leadership. Right before combat, a priest steps forward to address the army. The priest’s words are meant to steady the troops by naming the danger (“today… battle against your enemies”) and blocking multiple forms of panic (“don’t let your heart faint… don’t tremble… don’t be terrified”).
Where interpretation differs
Scope of the instruction: Some read this as guidance meant mainly for Israel’s land-taking wars (the immediate setting and type of conflict assumed). Others think it is stated broadly (“when you go out to battle”) to cover Israel’s wars more generally, beyond the initial entry.
What “to save you” means in wartime: Some take “save” as a promise of victory or survival in the specific battle. Others read it as broader protection and deliverance (God’s help in the conflict without guaranteeing that every soldier will be unharmed).
How to picture God “going with” and “fighting for” Israel: Some hear straightforward divine action language—God actively ensures Israel’s success against enemies. Others stress that the passage’s focus is reassurance and morale: God’s presence is real, but the statement is not a detailed claim about how every battle will turn out.
Why the disagreement exists
The passage is strongly encouraging but not highly specific. It gives reasons (“Yahweh… is with you… goes with you”) and purpose (“to fight… to save you”) without spelling out outcomes in measurable terms. It also speaks generally (“when you go out”) while being placed in a section tied to life in the land, so readers weigh grammar (“when you go out”) against setting (Israel preparing for conflict as they enter Canaan).
What this passage clearly contributes
It presents war, in Israel’s covenant setting, as a moment where fear is addressed through authoritative public speech grounded in God’s past deliverance (Egypt) and present presence. Explicitly, it says Israel may face superior forces, must not give in to panic, and should understand Yahweh as the one who goes with them against their enemies. Theological inferences may go further, but the text itself centers on courage grounded in Yahweh’s accompanying presence and rescuing action.