The point at issue—whether homosexuality, capitalism, colonial slavery, or something else—is never the whole of what is at stake. Nobody has to make a decision about that and that alone. It would be nice to purify the question to the point when it was about one thing and one thing only; but if we had done that, it would already be nine tenths solved. The question is always, what does it mean, in this constellation of circumstances, to approve or disapprove this or that line of conduct? What relations are present to us in and through it? How do the various refractions of the demand of love within the moral law come together to form an understanding of where we stand? So what looks “small” at first glance can become the subject of the day, the focus of everyone’s attention, the test of where each and every person is morally situated, the divide between old friendships and new ones. From outside the historical context it may be hard indeed to comprehend why; but it is part and parcel of historical understanding that we should recognize how one issue acts as a conduit for others.
That’s Oliver O'Donovan, quoted in a detailed, illuminating, and thoughtful review-essay by Christopher Benson, “A Better Conversation about Homosexuality.”