Twelve Ordinary Men works through the apostles one at a time, drawing from the Gospels what can be known of each: Peter's impulsiveness, the ambition of James and John, Thomas's melancholy doubt, Matthew the tax collector, Simon the Zealot, the obscurity of the lesser-known six, and Judas. MacArthur declines to idealize them, showing men of ordinary ability and visible faults whom Christ called, taught, corrected and finally sent out.

The encouragement of the book is plain: if Christ built His church through these men, He is not waiting for better material. It reads well devotionally and works particularly well in men's groups and small group studies, and the biographical approach makes it an accessible entry point for readers who find doctrinal books heavy going.