I believe they tell you this in aa. Its a life long disease. Aa is meant to help and deal with cravings but not cure. Sadly along with his sponsor and follow aa members no one can simply talk him to chamge his mind. He has to do that himself much like the first time.
Alot of addicts go without for so long they feel they can now "handle" or "control" it and relapse.
I know its painful but he needs to figure it out for himself hopefully he learns quick