Star Wars fans around the world are mourning the death of Carrie Fisher, the actress famous for her portrayal of Princess Leia in the original trilogy.

It is without a doubt, the role that defined her career and for which she will be best remembered, but off-screen, Fisher was a source of inspiration for other reasons, not least as a witty author and speaker, and a spokesperson for mental health issues.

She spoke often about her own experience with bipolar disorder and depression, and recounted struggles with drug abuse and alcoholism with honesty and even humor.

Her experiences were recently recounted in her autobiographical book Wishful Drinking, which later formed the basis for the documentary film of the same name streamed on HBO.

One of her most memorable quotes from the book revealed the extent of her battle with her own demons: "Sometimes you can only find Heaven by slowly backing away from Hell."

Despite her personal struggles, religion had little appeal to Fisher, even if the concept of God did.

She was quoted once as saying: "I love the idea of God, but it's not stylistically in keeping with the way I function. I would describe myself as an enthusiastic agnostic who would be happy to be shown that there is a God. I can see that people who believe in God are happier. My brother is. My dad is, too. But I doubt." 

In April this year, she accepted the Outstanding Lifetime Achievement Award in Cultural Humanism from the Harvard Community of Humanists, Atheists, And Agnostics, and the Humanist Hub, an award given to celebrities who are open about their atheism or agnosticism.

Yet she was never harsh in her agnosticism. When in 2015 a Church of England advert featuring the Lord's Prayer was banned from being shown in UK cinemas before Star Wars: the Force Awakens played on the big screens for fear of offending audiences, she was bemused.

"I have no idea why they would do that," she said. "Offended? No. People should get a life. I don't think it is offensive to have a 'power of prayer' advert before Star Wars." 

In the end, though, Fisher never found an answer to life's big questions in the concept of God or organized religion.

That was her brother, Todd Fisher, who became a born again Christian in 1980, being ordained two years later and going on to found a church with musician Henry Cutrona. 

According to one report, Carrie had once quipped that her brother had turned out normal except for being a born-again Christian.

In Carrie's final days, her family thanked fans and well-wishers for their love and prayers. Now they, along with the world, mourn her passing.

Her daughter, Billie Lourd, 24, said in a statement confirming her death: "She was loved by the world and she will be missed profoundly. Our entire family thanks you for your thoughts and prayers."