Browse through Amazon Books and you will find the whole spectrum - uplifting stories of the Christian faith, exhilirating tales of courage or intrigue, mindblowing facts about our universe, and seedy works of erotic fiction. And the quality of the writing is just as interesting as the range.

Amazon's list of top 20 best-selling books of all time reveals what they are reading most.

It will be more disappointing than surprising to most Christians to know there are no fewer than three works of erotic fiction in the top 20 list and it will be no surprise at all to discover they all belong to that now famous series, Fifty Shades. 

Fifty Shades of Grey, Fifty Shades Darker and Fifty Shades Freed by E.L.James are all there - an incredible feat by the self-published writer who is the only writer alongside Hunger Games writer Suzanne Collins to have more than one book in the top 20 - she also has three.  

Not even J.K. Rowling managed that, although she does feature one time with Harry Potter and the Deathly Hallows, the critically acclaimed conclusion to the massively popular series of children's books about a young boy wizard.

But it's nice to see two Christians books have made it to the list.  They are Laura Hillenbrand's Unbroken, the story of a bitter former prisoner of war under the Japanese who is finally able to forgive his captors after hearing the Gospel. The second is Heaven is For Real, based on the true story of a four-year-old boy who goes in for life-saving surgery and emerges with remarkable tales about visiting Heaven. 

In no particular order, here are Amazon's top 20 best-selling books of all time: 

Fifty Shades of Grey - E.L. James

The Hunger Games (Book 1) - Suzanne Collins 

Catching Fire (The Hunger Games) - Suzanne Collins 

Mockingjay (The Hunger Games) - Suzanne Collins 

Fifty Shades Darker - E.L. James 

StrengthsFinder 2.0 - Tom Rath

Gone Girl - Gillian Flynn 

Fifty Shades Freed - E.L.James

The Help - Kathryn Stockett 

Unbroken: A World War II Story of Survival, Resilience and Redemption - Laura Hillenbrand 

The Fault in Our Stars - John Green 

The Girl on the Train - Paula Hawkins 

Divergent - Veronica Roth 

Harry Potter and the Deathly Hallows - J.K.Rowling 

Heaven is for Real - Todd Burpo, Lynn Vincent 

The Girl with the Dragon Tattoo - Stieg Larsson, Reg Keeland 

Who Moved My Cheese? - Spencer Johnson, Kenneth Blanchard 

The Husband's Secret - Liane Moriarty 

A Games of Thrones - George R.R.Martin 

The Goldfinch - Donna Tartt