Tell us what you've done so far?
Seriously, we need information. Is the phone unlocked/rooted (the red text suggests it might be)? What other modifications have you made? When did the problem start, and what is the problem - I'm guessing it's stuck on the splash screen. Did you accept any software updates? What did you do before the problem started? What model/carrier is the phone?
If we know the phone's history and what happened leading up to it being in this state, we'll be able to give more accurate advice on what to do about it.
Without that, all I can suggest is forcing a shutdown (hold power button down for 10 seconds), going into recovery and doing a factory reset. But if we know more we may be able to come up with something better.