The self-professed "anti-religious" singer has revealed he became a Druid after studying the spiritual movement - which focuses on a connection to the natural world and is aimed at people who have become disheartened by religion - whilst making his latest solo album, 'Chaos and a Dancing Star'.
The 'Melancholy Rose' singer told the Daily Star newspaper's Wired column: “I’m anti-religious, but I’m looking for a spiritual aspect to my life to put in where I feel that lacking.
“I sent off for the book and CD about becoming a Druid and a scroll arrived in the post which says: ‘You could become a Druid.’
“And now I’m studying the books about it.”
Marc is an animal lover and even adopted a jackdaw named Dawkins - which he previously admitted he has become "very attached to" - and he explained that the record explores death and nature.
He said: “The songs celebrate the idea of returning to Earth.
“Because I’m not religious, I’m writing about the idea of nothingness, what will happen when the Earth swallows me up again one day.”
The 62-year-old star - who shot to fame as a member of synth-pop group Soft Cell in the early 80s' - previously described the tracks on the record as "apocalyptic love songs".
He said: "It reflects on mortality and uses a lot of nature references.
"They are apocalyptic love songs.
"I'm getting older and I've always loved cities, but I feel I am drawing away from that now and have a love for getting back to nature."
Marc is a huge fan of TV’s nature programme 'Winterwatch' and also admitted he "likes the idea of dancing around" Stonehenge - a monument in Wiltshire, England, which was built by a group of Celtic pagans (Druids) and hosts the annual summer solstice ceremony - "in robes".
He added: "I feel a calling back to a kind of paganism which started to come through on 'The Velvet Trail' [his 2015 LP].
"I like the idea of dancing around Stonehenge in robes."