iMessage not accepting my Apple ID
My phone is all set up, except for one nagging thing. I cannot get my Apple ID to work with the set up of iMessage on my phone. The same Apple ID I use to enter this forum, the same ID I use to download apps from the App Store "on my phone," the same ID I use for Facetime IS NOT WORKING to activate iMessage.
Does anyone have an idea about how I can fix this nagging problem? I do not want to change my Password, because I know it is already working.
Thanks!
iPhone 5s, iOS 8.1.3