In 1914, when the First World War broke out, St. Thérèse appeared some forty times to soldiers in various battlefields in France. The soldiers said she spoke to them matter-of-factly, resolved their doubts, helped them overcome their temptations, and calmed their fears. Thousands of French soldiers carried her photo and invoked her as “my little sister of the trenches,” “the shield of soldiers,” “the angel of battles” and “my dear little Captain.” A soldier wrote, “In fact, that gentle Saint will be the great heroine of this war.” Another commented, “I think of her whenever the cannons thunder.”

Countless were the artillery pieces and planes named after her; whole regiments were consecrated to her. Medals of the saint given to the soldiers miraculously stopped rifle bullets like real shields, saving the lives of the soldiers who carried them (some of these medals are now preserved in the cloister in Lisieux).

Before she died, she had told Mother Agnes, “I had a dream there were not enough soldiers for a war against the Prussians. You said, ‘We need to send Sister Thérèse.’ I answered that I would prefer to fight in a holy war, but I went all the same.”