Almost everything about services at St Bartholomew the Great church is old-fashioned. Purple-robed choristers process through clouds of pungent incense. The priest, the Rev Marcus Walker, brandishes an ornate golden King James Bible above his head before reading from the 1611 text. The liturgy is a mixture of 16th-century prose and sung Latin. The medieval priory church, which sits a stone’s throw from the central London hospital of the same name, was founded in 1123.

However, the congregation watching on at a recent service were younger than most would expect; at least a quarter were under 35. They had come to observe a handful of men and women, mostly in their late twenties, be baptised into the Anglican faith. Afterwards the millennials gathered inside the