Your article on the Bishop of Oxford’s intervention on CofE school admissions (“CofE to throw open school gates to mass of non-believers”, 22 April) focused on statistics.

What percentage exactly of places should be reserved for children from church families? Ten per cent, as the Bishop suggests? Thirty-three per cent, as indicated by the director of education in the dioceses of Bradford and Ripon and Leeds? Or 100 per cent, the wish of some parents, no doubt?

But this debate misses the significance of the Bishop’s comments, which raise the question of the purpose of CofE schools. In his view they are part of the mission of the church. He echoes the words of the 2001 Dearing report, which said church schools should offer a distinctively Christian education. As far as the Bishop is concerned, this isn’t about collecting “nice Christians into safe places”.

The danger is that his call to reduce the places reserved for church families is interpreted as a desire to water down the distinctiveness of church schools. Not so. Rather it is a call to recognise that the mission of the church is to serve the whole community, showing that the message of Jesus is for the mainstream.

The really important question raised by the Bishop is how CofE schools will create a distinctively Christian ethos. Family backgrounds of pupils will be a factor, but more important will be the clarity of vision and purpose of governors and staff.

Research that I have undertaken with Dr Elizabeth Green at Liverpool Hope University reveals that lack of understanding of this mission is the key challenge facing Christian “faith” schools. Admissions policies are important, but they are insignificant in a situation where many school leaders don’t understand how to implement their calling to create a distinctively Christian school.

Professor Trevor Cooling, National Institute for Christian Education Research, Canterbury Christ Church University.