Spirituality being essential to treatment never made sense to me. If addiction is a disease, why are we “treating” it with spirituality?

Spirituality being essential to treatment never made sense to me. If addiction is a disease, why are we “treating” it with spirituality?
Refuge Recovery is a fellowship of men and women for whom addictions have created a major problem in their lives. The program is based on the principles of Buddhism: particularly the Four Noble Truths & the Eightfold Path. Refuge Recovery is in alternative to the traditional 12-Step Approach to recovery.
Gateway Theory, if you’re a product of the D.A.R.E. generation you’ve no doubt heard of the concept. Get introduced to “soft” drugs like alcohol or marijuana and you’re all but guaranteed to turn into a heroin addict. Is it true?