edit: really - addictions don't live inside you, perched on your heart, making you do bad things. They are not different than you.
edit: really? Happy to accept the downvotes on this one.
A homunculus didn't do it; I am it and I did that.
That's what the demons want you to think.
Many of your behaviors are effectively semi-autonomous reactions perched inside you.
Sure, we know from science and Occam's razor that devils and gods probably don't exist, but that doesn't mean participating doesn't show proven benefits. Although the studies that show the benefits of religion tend to find attendance means more than believe, so it is more of a network and support effect than anything actually spiritual.
Ministries are not known for their careful scientific rigor in defining and measuring success rates. That 50% could be coming from any of a number of biases ranging from blatant to subtle: "How to have a high success rate in treatment: advice for evaluators of alcoholism programs", Miller & Sanchez-Craig 1996 http://slatestarcodex.com/Stuff/addiction.pdf is a semi-humorous paper from some frustrated researchers describing how these bogus numbers come about (discussion: http://slatestarcodex.com/2014/01/02/two-dark-side-statistic... ).
http://en.wikipedia.org/wiki/G%C3%B6del's_incompleteness_the...
Come off it - where's the control group, where's the blinding, how big is the sample size, etc etc.
edit: and everything that you said is true. Don't be discouraged by the downvotes. People are downvoting facts that they don't that don't accord with with their prejudices, rather than people participating in bad faith or spreading misinformation.