Instead of "struck fear into," there are several antonyms that can be used to describe emotions or actions that inspire confidence, hope, or optimism. Rather than instilling terror, they may bring comfort and reassurance. Alternatives to "struck fear into" could include "calmed," "comforted," "encouraged," "enlightened," "inspired," or "reassured." These antonyms may be used in different contexts, such as soothing someone experiencing anxiety or uplifting someone in despair. As with any word choice, it is important to consider the tone and purpose of the sentence and choose the most appropriate synonym to convey the intended message.