This is a concise introduction to Christian theology from a classically evangelical and reformed perspective, and is the best such book that I've read. Hammond's style is pithy and memorable, and his passion for thorough, robust and biblical doctrine shines through in his writing. Scripture references are called out in each section, and his handling of difficult doctrines is skilful and balanced.
I would recommend this to young Christians as a clear and accessible introduction to the outlines of theology, and equally, it serves as a great refresher to someone who is more mature in the faith. It is one of the few books that I try to reread every year, and each time I do, I find my understanding and affection for these doctrines deepened. In this short book, Hammond has given the church a fantastic and timeless gift.