a childrens school book from the 1950s about "Outer Darkness" and a strong religious theme

[Liz]

Hello, My mother who has dementia has become obsessed with finding a book she read at school in the uk as a child. That would be in the 1950s as she is 80 now. So obviously the book would be older. All she can tell me is that the main character was called Christian, or WAS Christian, and there was much talk of "Outer Darkness". She can't remember anything else except that the book put her off reading!
Can anyone help please? Thank you!

[Lobstergirl, au gratin]

A Modern Utopia by H.G. Wells contains references to "Outer Darkness" in its Appendix.

Possibly That Hideous Strength by C.S. Lewis? He was Christian, and there are lots of references to Christian(ity) in the book.

The Rogue's March: A Romance by E.W. Hornung has a chapter titled "The outer Darkness." So does The Hundredth Chance by Ethel M. Dell.

The K.K.K by Charles Waller Tyler has references to Outer Darkness.

Up and Down by E.F. Benson?

Or was the book for a younger child? Did it have illustrations?
Cover art? Author's gender?

[Pamela]

Possibly The Pilgrim's Progress, by John Bunyan? The main character is named Christian. The Pilgrim's Progress

[Kris]

Liz, what's the genre - e.g., for kids or teens? fantasy, science fiction, horror, etc.?

Try adding more plot details to the header/ topic title ("a school book..."). You can copy from what you've already written in the first comment. Someone is more likely to recognize your book. If you would like help with this, just post a new comment.

[Liz]

Thank you everyone for your comments. I'll try to improve my post. I will try the suggestions on my mother and try to get more detail. Anything!
Thank you again.