Pastor and author J.D. Greear explains the basic story of Christianity in this book, focusing on different foundational elements of faith in each chapter. Greear's writing style is conversational, honest, and humorous, and he writes about complex ideas in ways that people can connect to regardless of their existing background with faith or level of interest in theology or philosophy.
"Essential Christianity" will help and encourage Christians who want to better understand and articulate their beliefs, and it is accessible to skeptics who are curious about Christianity. However, I don't think that this book will be useful to many people who are deconstructing childhood faith. Greear writes in an understanding way about why many young adults are leaving the institutional church and questioning their faith, but the book doesn't say anything that lapsed or questioning evangelicals haven't heard before. It's best for people who already agree with Greear or have never heard or considered what he's saying.
On a related note, I didn't think that the intermission regarding same-sex sexuality was helpful. Greear needed to include it instead of skipping over controversial verses in his source material, but he didn't add anything new to a contentious conversation that is a hang-up for many people considering faith. This doesn't address current shifts in the debate and won't change anyone's mind, and Greear doesn't engage with any alternate interpretations of those verses in Romans, not even to argue against them.
Overall, I would recommend "Essential Christianity" to Christians, and to skeptics who are curious about the Christian faith and want to read a book that covers a wide variety of information in a highly readable way, instead of taking scholarly deep dives. This is a good introduction to foundational Christian beliefs, even though I think it could have been better.
Disclaimer: I received a free copy from the publisher in exchange for an honest review.