Why I Am a Lutheran by Daniel Preus

Preus does an awesome job of addressing the central doctrines of sin, grace, Law and Gospel, the Sacraments, worship, ministry, etc., always focusing on how Jesus is at the center of all Christian teaching. He lays things out in a way that's easy for people to understand and beautifully speaks of what Christ has done for us. Excerpts from this book can be found in my theology posts. Awesome book!