Yup, they say alcohol or drugs are just a symptom of a spiritual ailment and I believe it 100%. There are core issues here and the substances help numb and cover what we can't cope with.
It's hard with alcohol, I know...his family drinks wine, there are weddings and toasts and holidays full of ceremonial drinking. And it's almost as if one is shunned or stigmatized for not partaking in alcohol related celebrations whereas it's not the case at all with drugs.
We certainly can't influence what they do but I think your husband is at least on the right track and a program is absolutely essential for recovery.