In the summer of 1968, between college and seminary, I read Martyn Lloyd-Jones’sStudies in the Sermon on the Mount. It was then, and is now, spiritually and theologically powerful. Lloyd-Jones was one of the best preachers of the 20th century. Thanks to the grace of digital technology, he still is.

Now these 656 pages are recorded by Chris Allen in five apps for your phone, with about six hours of reading in each app. What is unusual about these apps is that the text of the book scrolls as they are read to you — or you can just read. It’s like getting an audio book and ebook and a player, all in one.

Besides the scrolling text and the audio, there is a built-in glossary of unusual or culturally distant terms, and other “extras.”

These have been my exercise-at-the gym listening for the past several weeks. Main reaction: conviction, longing, worship.

If you are a book-listener or ebook reader, Lloyd-Jones’s Studies in the Sermon on the Mount is a classic worth your investment of time and money.

John Piper (@JohnPiper) is founder and teacher of desiringGod.org. He served for 32 years as pastor of Bethlehem Baptist Church, Minneapolis, Minnesota. He is author of more than 50 books. John and his wife Noël have five children and twelve grandchildren.