The Archbishop of York, the Church of England's second most senior clergyman, says he would be "hard-pushed" to say Britain was a Christian country.
Dr Hope has been Archbishop of York since 1995
Speaking on BBC's Breakfast with Frost Dr David Hope said commitment to the church had diminished while secularist tendencies had increased.
But he said he was encouraged by the numbers of people who did attend church regularly.
Dr Hope resigns his post to become a parish priest in Ilkley in January.
He said: "Large numbers of people still describe themselves as believing in God.
"Large numbers of people still say they are Christians.
"How they then express that Christianity has changed enormously."
Dr Hope said he would be glad to "downsize" to becoming a parish priest.
"I always felt I would like to finish my ministry as I began it, and that is as a parish priest.
"Increasingly these days we are weighed down with bureaucracy and that is as true in the church as anywhere else.
"I think I shall be quite glad to be rid of all that."
Dr Hope will become vicar of St Margaret's in Ilkley, West Yorkshire.