Rushing and Passing balance each other out. If they’re both strong, then you have a great offense, not only in part because of the strength of each method but also because it makes the defense more careful.
If one or the other is not near as strong, it allows the defense to sandbag.
If we can get a passing game on par with our running game, even if neither is top-of-the-PAC or world class, it will help the entire offense immensely.