Mold will not die if it dries out because mold is a living organism. However, if moldy items dry out, the wet parts evaporate, and they’ll let off spores that can spread to new areas. In addition, when there’s water moisture in the air, like, for example, in your bathroom or shower, all sorts of icky creatures will gravitate towards those areas. Yet another reason why you want your home dry when dealing with anything mold-related.