Christ before politics, so no one should be playing at excluding others.

In my experience, the work of a Christian youth leader is essentially a pastoral role. Churches don’t run youth groups just to keep young people off the streets, but to enable young people who wish to grow in the Christian faith the opportunity to do so. There is no meaningful sense in which a non-believer would be able to assist young people in living Christian lives – by which I mean not only following the teachings of Christ but engaging in a personal relationship with Him through prayer, meditation, reading the Scriptures, and so forth. The best youth workers tend to be those who model Christ-likeness in their own lives and who open up their hearts and homes to the young people with whom they work. Christian youth work therefore has much more in common with ordained ministry than with, for instance, the work of a church caretaker.

Certainly, Liberalism requires a belief in equal opportunities in the labour market, but I think the historic Liberal belief in the right of individuals and groups to practice their religion (or non-religion) according to their own lights, so long as it does not impinge on the human dignity of other citizens, is more fundamental.

Other notable offenders (albeit far less serious) and certain libraries and swimming pools.

They are free to set policies on how the youth group should be run, to make those policies consistent with their religion, and to hire people on the basis of their ability to carry out those policies. They are even free to require candidates to have an interest in the religion. They are not free to say that a person who is not a member of the religion is incapable of carrying out those policies.

I would expect that in most but not all cases, the person best suited under those criteria would in fact be a member of their religion. The whole point of non-discrimination laws is that they are not allowed to exclude the inconvenient few who can do the job but don’t fit the norm.