Consistency is difficult, but it is necessary in order to communicate a message thoroughly. This goes hand-in-hand with your brand. There are reasons for why your logo is shaped the way it is, why you use specific colors and why there are all kinds of rules for what you can and what you can’t use when representing your brand.
This is not to say that you shouldn’t allow for creativity within the boundaries of your brand’s system. Think of it as thinking inside the box. What can you do with your brand that is both creative and consistent?