iMessage on my iPhone works perfectly.
Just telling us that iMessages on your iPhone does not work isn't ging to get you anyhelp. No one here wants to play "ask 20 questions." No one here wants to make suggestions to which your reply is, " I already did that."
If you want help, then you will need to explain how you have configured iMessages on your iPhone, what happens when you try to use the service, what solutions you have attempted in your efforts to solve the problem yourself and what the results were.