source: http://bsa-30.natcen.ac.uk/read-the-report/key-findings/identities.aspx
Less religious attachment
We start by examining whether people's attachments to these three identities are indeed in decline, beginning with religion. Here there is little doubt that a substantial change has taken place, with a marked decline in the proportion who describe themselves as belonging to a particular religion. In 1983, around two in three people (68 per cent) considered themselves to belong to one religion or another; in 2012, only around half (52 per cent) do so. As our Personal relationships chapter sets out, this decline is in practice a decline in attachment to Anglicanism; in 1983 two in five people (40 per cent) said they were Anglican, and the Church of England could still reasonably lay claim to being England's national church (and thus, arguably, to some extent its fount of moral authority). But now only 20 per cent do so. In contrast, the proportion saying they belong to a religion other than Christianity has tripled from two to six per cent. Britain's religious landscape has not only become smaller but also more diverse.[2] 
