One of the great benefits of growing up with a pastor for a dad is that you can raid his library. I am not sure at what age I found this gem in his library, but I remember I was at least in junior high. This book helped me understand and dig deeper in theology.
The Moody Handbook of Theology is broken down into five parts: Biblical theology, systematic theology, historical theology, dogmatic theology, and contemporary theology. I overwhelmingly found the first two sections my personal favorites & have marked in them extensively.
The layout of the work is like a textbook, with headings and charts and graphs, but it is extremely well-written. It is nowhere near as extensive as either Grudem's Systematic Theology or Erickson's Christian Theology, but a good starter theology and one that will dive you a good taste for theology. I found both this book and Erickson invaluable in my time at TEDS.
A great features of this volume is the interaction of the different disciplines, comparing and contrasting them. It also looks at many of the different theories and succinctly boils them down and makes them digestible. This was one of the reasons I grabbed this book at such a young age. I could easily understand many, if not most of the concepts (as much as anyone can understand some of the mysteries of our great faith). This would be a great volume to pass on to those who want a basic understanding of theology, and one that is simple to read and manageable.