This volume addresses God the Father, Son, and Holy Spirit as Gerhard explores the divine names, God's existence, the divine essence, and the mystery of the Trinity. As Gerhard makes the argument for the Trinity, he turns repeatedly to Holy Scripture as his source. He interacts with the writings of the ancient church fathers, but he points out the heresies that have arisen and the responses. He speciifically addresses the arguments of the Photinians concerning the Trinity.Useful for research on Lutheran doctrine, Gerhard's accessible style makes this a must-have on the bookshelf of pastors and professional church workers.