Wonderful Short Book on a Great Man of God
There are longer biographical text on the man; Martin Luther, but I doubt there are any more concise volumes that celebrate the man and his ministry.
I learned more about Luther from this book than perhaps any other. Its chapters are short and concise and focused on the many aspects that made Martin Luther the man, the minister, and the Reformer that he was. For example, he was a prolific preacher but was scared every time he stood up to preach.
If you are looking for a quick read, I would highly recommend this one. Coming in at only 117 pages with short chapters, I believe this is one of the best biographies I’ve read.