Many adult books also come in kids’ versions.
One of those is Lee Strobel’s Case for Grace For Kids.
Each chapter in the book is a true account of people who have accepted God’s gift of grace. The accounts vary widely from a young boy who saved his school bus driver’s life to a son who grew up in a good home, but then strayed from the Lord.
Knowing kids fairly well, I think this book would best be used in a class situation. Are you doing a summer program at your church or a kids’ Bible study? My suggestion would be to read and discuss one chapter per class. I think that would work better than having a kid sit down and read it straight through. (But just a suggestion.)
The book is for older elementaries and up. Younger kids might not understand all the situations – unless read by a parent with a child. (In other words, if a parent was right there to explain.)
The book is available on amazon.com