In his book Why Should Anyone Believe Anything At All, James Sire recommends the following books on The Problem of Evil:

The Problem of War in the Old Testament, by Peter C. Craigie

Making Sense Out Of Suffering, by Peter Kreeft

A Grief Observed, by C. S. Lewis

The Problem of Pain, by C. S. Lewis

The Enigma of Evil, by John Wenham

The following books are recommended in How Could God Allow Suffering And Evil?, a small group curriculum published by Willow Creek Resources.

I’m Glad You Asked, by Ken Boa and Larry Moody

Letters From a Skeptic, by Gregory Boyd and Edward Boyd

The Gift of Pain, by Paul Brand and Philip Yancey

Why Believe?, by C. Stephen Evans

Christianity Made Simple, by David Hewetson and David Miller

Give Me an Answer, by Cliffe Knechtle

Help Me Believe, by Cliffe Knechtle

Finding Faith, by Andrew Knowles

Handbook of Christian Apologetics, Peter Kreeft and Ronald Tacelli

A Grief Observed, by C.S. Lewis

Mere Christianity, by C.S. Lewis

Miracles, by C.S. Lewis

The Screwtape Letters, by C.S. Lewis

Know What You Believe, by Paul Little

Know Why You Believe, by Paul Little

Kingdom of the Cults, by Walter Martin

So What’s the Difference, by Fritz Ridenour

The Case for Christ, by Lee Strobel

The Case for Faith, by Lee Strobel

Disappointment with God, by Philip Yancey

Where is God When it Hurts?, By Philip Yancey

The study Why: 40 Days Pursuing Answers To Life’s Biggest Questions recommends the following books for answering the question, “Why Is The World So Messed Up?”

Evil and the Cross, by Henri Blocher

Is God to Blame, by Gregory Boyd

Satan And The Problem of Evil, by Gregory Boyd

The Problem of Pain, by C.S. Lewis

How Could God Allow Suffering and Evil? Tough Questions, by Garry Poole

A Grace Disguised: How the Soul Grows Through Loss, by Gerald Sittser

Can God Be Trusted?, by John Stackhouse