While many may find the Message Preview in the notification bar a useful feature on Android, some may find it against their privacy. To disable Message Preview on Huawei Ascend P6, do as follows:
1. Open Messaging application
2. Tap the 3dot icon on the bottom right, and go to Settings.
3. Scroll down and under Notifications settings, make sure to unmark the "Message Preview" option to disable the feature
*To enable Preview Message in the notification bar, you just need to mark the "Message Preview"