For religion to be as successful as it is in our society there must be some benefits, otherwise it would die out; IMHO religion would die out if it was purely driven by fear.
It is an interesting study - although I would be worried the first study is suffering by a bit of confirmation bias...Lisa Miller seems to be part of the "SCP" which ...
Spirituality in Clinical Practice (SCP), a journal of the American Psychological Association, is a practice-oriented journal that encompasses spiritually-oriented psychotherapy and spirituality-sensitive cultural approaches to treatment and wellness. SCP is dedicated to integrating psychospiritual and other spiritually-oriented interventions involved in psychotherapy, consultation, coaching, health, and wellness.
It would be interesting to see if other unidentified factors were at play in the Miller study. Perhaps if the questions from the original study were followed up by "I have a healthy relationship with my parents... and I would turn to them when I need help"- I wonder if the responses to that question would yield similar results when related to depression?
Also, it would be interesting to follow up the outliers in the study... do fanatical religious groups have negative effects when compared to the study? Does the 'zeal' of one's spirituality (if that can be measured) have an effect? etc... The Dew study was interesting in this front.
Are there links between socio-economic factors and religion? That too would be interesting.
Why do I not 'sign up'? Well I realise that my two kiddies need something in their life to help them through the hard times... the something is our family, their education, their interests and hobbies which I support fully. I do not think religion would add anything. In fact if my experience is anything to go by, it would only detract.