Is it OK for prime ministers to 'do God' in public?

At an Easter reception in Downing Street, David Cameron ventured where even Tony Blair feared to tread, quoting from the Gospel of Luke, speaking of 'we Christians', and welcoming the Christian 'fightback'. 'The values of the Bible, the values of Christianity, are the values that we need', he said. In your view, is it acceptable for a modern prime minister to espouse Christian values so openly?