I applied once to a Catholic school - without being Catholic - and therefore had to just leave this section blank (unless I had bribed a priest...) They still appointed me though. Faith schools are looking for the best candidate who also supports their faith (but doesn't necessarily actively practise it). They therefore expect this section to be left blank if the candidate does not have a regular chucrh / priest who knows them enough to do a reference - this is ok. However, seen as you have actually occasionally been to church, the vicar should be able to give you a reference albeit a slightly vague one! Don't worry about it - it won't necessarily be a stumbling block. Most of the other candidates are unlikely to have a vicar reference at all!!!!