Ex-Men Behaving Badly star Neil Morrissey and Paul Daniels' widow Debbie McGee have signed up to "live as pilgrims" for a new BBC show.
The Pilgrimage, a three-part series, will track famous faces - some religious and others atheists - as they swap the comforts and trappings of fame for 15 days to take part in Spain's Camino de Santiago.
"Living as simple pilgrims", they will stay in traditional hostels and "carry everything they need on their backs" while embarking on their "own spiritual journey" on BBC2.
Comedian Ed Byrne, ex-Gogglebox star the Rev Kate Bottley, M People singer Heather Small, journalist Raphael Rowe and JJ Chalmers, a former Royal Marines Commando who was wounded in Afghanistan, are also taking part in the medieval pilgrim route.
The series will combine "religious and spiritual debate" with "personal stories of self-discovery," the BBC said, with the physical challenge proving too much for some.
The series will "show how a group of well-known faces, taken out of their comfort zone, discover what their faith means to them as they walk in the footsteps of ancient pilgrims," BBC religion commissioning editor Fatima Salaria said.
The Pilgrimage is among several new programmes on religion and ethics announced for BBC1 and its sister channel.
Historian Dr David Starkey will reveal "how the Protestant Reformation unleashed fundamentalist beliefs, terror and holy war across Europe in a way that is all too familiar to us today", the BBC said.
His one-hour, BBC2 documentary, filmed in Rome, Germany and the UK, will chart the spread of Martin Luther's ideas across Europe and into Britain.
The historian argues that Henry VIII's break with Rome was a "Tudor Brexit" that laid the foundations for conflicted attitudes to Europe today.
"There was the same literalism, the same passionate intensity, the same apocalyptic violence as now," he said.
On BBC1, Earth's Sacred Wonders will feature some of the greatest spiritual buildings and religious sites, while a strand of five films a year will explore faith and ethical issues in Christianity, Hinduism, Islam, Judaism and Sikhism.
They include The Hotel For Refugees, a film about a small Irish Catholic community grappling with the impact of the arrival of Syrian refugees, and The Jews Of Canvey Island, which follows the North London Hasidic Jewish community as they relocate from urban Hackney to Canvey Island in Essex.
The BBC said Christian programming will remain the cornerstone of its religious output, citing live worship as well as Songs of Praise, Sunday Morning Live and The Big Questions.