Remember that he is 14 years old and lacks the the maturity and empathy that one would desire. He may underlying his behavior be trying to protect himself from the psychological pain of being greatly disapppointed and let down by an older brother who typically acts as role model. Given what you said about your faith, I would recommend a faith based child psychologist. He is apparently reticent to speak with any others present and although family therapy would be ideal, it is not appropriate in all situations (I am a family therapist) so I would not recommend family therapy and I would assure him that what he said would be held in confindence by the psychologist (unless it was life threatening). I have dealt with several situations where the child would not speak in front of his parents, but would alone, and further along obtained the child's permission to share some material. In addition he may be able to elicit what is going on from administering psychometic testing. Good luck and best wishes.
If you require further clarification or more information, feel free to ask!
Please click the green "ACCEPT" button on this page if you are satisfied with my answer so that I get credit for my work. Your positive feedback is most important and bonuses are always welcomed. If this is a mental health, or medical emergency, please call emergency services (911 in the USA), or go to your nearest Emergency Room. The opinion provided does not replace an evaluation by an appropriate professional. Use of this website DOES NOT CREATE a provider-client relation and this information is for educational purposes only.