Without more information about his behavioral changes it is impossible to guess what might be going on. You sound like you are really concerned for him. If the changes are extreme, especially with the irritability and the religiosity, then he may need evaluated by a mental health professional. He could be going through a particularly severe episode of Major Depressive Disorder, or even showing signs of Bipolar Disorder. Both can really mess with one's thinking.

Or...he may just be really crabby about something.

If you know someone in the MH field, or have a local community mental health center, you may call and describe your concerns to them and see if they recommend that you try to get him in to see some one. Otherwise, feel free to PM me with more details and I may be able to tell you if it is critical for him to be evaluated.

Janie