iMessage is one of my favorite application in iOS. It’s an exclusive one just because you’re able to use iMessage if you’re using an iOS device 🙂 . iMessage is a fast messaging application.
If you’d like to use iMessage , you need to activate  by enabling in the settings menu. Please take a look this pic :
This issue was happened usually if the traffic on the apple server is full such as when the new iOS is released or other case due to the traffic of your telecommunication operator itself.
I just try to disable and reset the network settings, but not solved yet. Then I try to sync to My MacBook Pro using iTunes, then “power off” the iPhone  and turn on it again. Just wait for some minutes and the iMessage is activated 🙂 . Thanks to 3rr0rists for sharing .
OK now 2.10 AM ~ I Miss you ~Â