The phrase "be wary" means to be cautious or careful, so its antonyms would be words that suggest the opposite, such as "be reckless," "be daring," or "be audacious." Other antonyms might include "be trusting," "be naive," or "be gullible." Of course, it's important to remember that being too reckless or trusting can also lead to negative consequences, so finding a balance between caution and confidence is key. Ultimately, the appropriate antonym for "be wary" depends on the context and the desired outcome, as well as personal values and beliefs.