1. Have you tried rebooting your device?
2. Have you tried resetting "all settings"?
3. Have you attempted to restore your device from a recent backup or during a time when a password worked?
5. Have you attempted to restore your device and set it up as new?
6. Have you tried log gin on to "Manage Your Apple ID" to make sure the Apple ID is verified?
If not, give the steps above a try.