Sorry... That is very vague. Could you join the site and reply in this thread with more detail?
Does the keyboard deploy (can you see it pop up)? Does it type and then disappear? Does it type and then stop? Does it not type at all? Is it type only with the problem? Does WordFlow (swipe) work or not?
What messaging? Is it the built in SMS or another App?
Do you have this keyboard problem on any other screens?
Try a Soft Reset. Hold the Volume Down + Power buttons until the phone vibrates and reboots (about 10 seconds). If that doesn't fix it get back to us with some more detail.