Any group that experiences a loss in membership and influence will blame the decline on a lack of purity to their core beliefs. It doesn't matter if those beliefs themselves are the cause of the decline, the retreat to fundamentalist purity is the inevitable response. Of course, since the problems with the SBC and evangelical Christianity in general are caused by their outdated and rather silly biblical interpretations, their retreat to purity merely accelerates their decline into irrelevancy. The SBC recently endured the largest decline in membership in its history, and the trend will worsen over the next several years.

As an aside, this will also be a huge problem for American Republicans because their base is the fastest shrinking voter base in the country.