Robert Letham?s book, The Holy Trinity (P&R, 2004) is a superior introduction to Trinitarian theology, certainly the most complete, reliable, and best treatise on the subject to come from a Reformed theologian for I don?t know how long. It covers the biblical bases for the doctrine, provides a long and lucid treatment of the development of the doctrine, and examines recent Trinitarian theology from Barth, Rahner, Moltmann, Pannenberg and Torrance, as well as Bulgakov, Lossky and Staniloae. His grasp of... Read more