Gwyneth Paltrow and Chris Martin's relationship reportedly hit the rocks five years ago when the actress started following Kabbalah.
The couple - who have children, Apple, nine, and Moses, seven - split up earlier this week after 11 years of marriage, but it's believed their relationship has been on the rocks since the actress began following the religion in 2009.
A source said: ''Chris wasn't happy about it. He felt that he was starting to lose the woman he fell in love with.''
The pair have been leading separate lives over the last couple of years as the 41-year-old star became more enveloped in her Goop lifestyle brand and Chris, 37, began recording the latest Coldplay record.
The source explained to The Sun newspaper: ''Chris is laid-back and low-key, and found it harder and harder to live up to her perfect standards.
''Gwyneth was focusing less on her showbiz career and more on her lifestyle projects.
''She also didn't feel like she got enough attention from Chris.''
It is believed Chris even moved out of the family's £7 million home in London's Belsize Park last year and began living in his bandmate Guy Berryman's small flat in Hampstead Heath, North West London.
The insider claimed: ''Chris was really struggling with Gwyneth. Their relationship was under huge strain and he was doing everything he could to patch things up. But he felt he had no choice but to move out. Guy offered him a place to stay where he could hide out and deal with it all.''