The Queen will use her traditional speech broadcast on Christmas Day to reflect on her personal faith and her belief in the enduring role of Christianity at the heart of British life.
She has chosen to deliver her most Christian message yet after a year of unprecedented brutality by Daesh, or Islamic State, carried out in the name of religion.
Dr Michael Nazir-Ali, former Bishop of Rochester and a leading expert on Islamist extremism, said: "Clearly extremism is a backdrop to anything that any public figures says at this time. If people in this country gave greater heed to what the Queen says about the importance of Christianity in our personal as well as our national life, then we would be in a better place to confront it.
"The Queen will also be aware that Christians and others have faced unprecedented persecution over the last year in parts of the Middle East, and could even face extinction."
Her son and heir to the throne Prince Charles has recently been speaking up for persecuted Christians in the Middle East.
The speech is known in Buckingham Palace as QXB, short for Queen's Xmas Broadcast.
A source told The Mail on Sunday: "Over the years we've seen a greater emphasis on the Queen's faith and we're certain to see it in this year's Christmas broadcast. There's a fundamental optimism which, to an extent, is driven by her faith in contrast to the overall gloom. She is driven by a deep and spirited faith."
Stephen Bates, author of Royalty Inc: Britain's Best-Known Brand, said the Queen, Supreme Governor of the Church of Engand, planned to use the speech to speak openly about her religious faith as a voice of calm and spirituality amid the tides of consumerism.
The Queen's message, which is pre-recorded, will go out on BBC1 and ITV at 3pm on Christmas Day. Last year it attracted 7.8 million viewers in the UK, nearly as many as the 8.4 million who watched the X-Factor final this year. She has a way to go though to catch up with the Strictly final last night, watched by 12 million.