In the UK religious freedom is a human right, but leaving your family's religion can still mean isolation and loneliness.
Sara has been speaking to Newsbeat about what it was like when she told her parents two years ago that she no longer wanted to be a Muslim.
"You feel like you're betraying everyone. Because no one leaves Islam," she says.
She says they kicked her out at 17 and she's not lived with them since.
In some countries, such as Qatar and Saudi Arabia, leaving Islam - or "apostasy" carries the death penalty.
"Most people I talk to feel like they're the only ex-Muslim in the world," says Sara.
As she got older she realised "that Islam didn't quite fit" with her thinking but she kept it a secret - lying about praying and studying Arabic. [BBC] Read more
