Thanks for stopping by the Apple Support Communities. From your post, I understand that your iPad mini is prompting you with an Activation Lock message. I'm happy to help you get this taken care of!
Activation Lock is a feature of Find My iPhone that protects your phone in the event it's misplaced or stolen. In order to activate an iPhone while Find My iPhone is active, you must sign in with the Apple ID and password used to set Find My iPhone up under the iCloud settings on the device.