The C. S. Lewis Signature Classics (8-Volume Box Set) by C. S. Lewis.
This set includes: Mere Christianity, The Screwtape Letters, The Great Divorce, The Problem of Pain, Miracles, A Grief Observed, Abolition of Man, and The Four Loves
"Clive Staples Lewis, (1898-1963) was one of the intellectual giants of the twentieth century and arguably one of the most influential writers of his day. He was a Fellow and Tutor in English Literature at Oxford University until 1954, when he was unanimously elected to the Chair of Medieval and Renaissance Literature at Cambridge University, a position he held until his retirement. He wrote more than thirty books, allowing him to reach a vast audience, and his works continue to attract thousands of new readers every year."
Reader's note: Mere Christianity and the Abolition of Man are perhaps his greatest works.
Links:
1. Internet Archive: The C. S. Lewis Signature Classics (8-Volume Box Set)
Source: https://www.logos.com/about-authors/c-s-lewis