Census data helps with the planning and funding at the Church of England
The Church of England uses census population figures at output area (OA) level to allocate funds to its 12,500 parishes, and uses lower super output area (LSOA) level attribute data to make specific grants to parishes. Population is regarded as a good indicator of likely need for funding for individual parishes.
The church also distributes grants for specific issues, for example The Near Neighbours programme. Grants are allocated to areas that meet particular criteria in terms of diversity. In order to assess parishes they need to transform the census data on ethnicity and religious affiliation onto parish boundaries. Similar exercises rely on LSOA deprivation data, converted onto parish boundaries by using census level (and now postcode level) population figures.
The Church of England has nearly 29,000 people licensed in some way to work in the church (clergy etc). To work out where these people need to be placed, the Church use population data to work out the likely demand in a given parish; more people means potentially more work for the church. It's important to have accurate local level data, including some population profile information.
The Church of England does a lot of work with other voluntary groups and increasingly with local government and public sector agencies. An example is dioceses using local data to understand where there might be a need for youth provision (using local level age data), and working with the statutory agencies to decide where the need is greatest.