But judges like  —  commentators — find cases like this interesting. Not unreasonably, they think that their opinions will be helpful, perhaps even to law students.

So Munby and Beatson developed the initial question into a series of legal propositions which they discussed in a judgment running to 34 closely-typed pages: Munby is not known for the brevity of his rulings. After 109 paragraphs, the court decided to make no order or declaration.

All this followed a one-day hearing last November, which cannot have been a very enjoyable occasion. The two claimants were represented by Paul Diamond, who is a committed Christian. We know this because at one point in the hearing he began a sentence with the phrase "I believe". Since his words introduced an expression of faith rather than a recollection, they will not have impressed the court.

Paradoxically, it is never a good idea for an advocate to be committed to his or her cause. In Paul Diamond's case, it led him to use what the court described as "extravagant rhetoric", as well as written assertions which the court dismissed as a "travesty of the reality". 

The judges were not dealing with the grant of state "benefits", despite what the barrister had claimed. "No one is asserting that Christians [...] are not ‘fit and proper' persons to foster or adopt," the court said. "No one is contending for a blanket ban. No one is seeking to de-legitimise Christianity or any other faith or belief [...] No one is asserting that the claimants are bigots."

However, the judges did conclude that a local authority (such as Derby) was "entitled to explore the extent to which prospective foster carers' beliefs may affect their behaviour [and] their treatment of a child being fostered by them". Although religious discrimination would be unlawful, a refusal to grant approval because of the couple's stance on sexual orientation would not amount to religious discrimination.

I am certain that Lord Justice Munby and Mr Justice Beatson have accurately summarised the law. But Christian campaign groups should, in the future, direct their criticism towards the politicians who make law rather than at the judges who enforce it. Better still, they should avoid using tendentious arguments in support of claims which are unwinnable.