Gerhard, Johann an eminent theologian of the Lutheran Church of Germany, was born in Quedlinburg October 17, 1582. In 1599 he went to the University of Wittenberg, and studied medicine for a time, then went to Jena, where he privately studied Hebrew, the Scriptures, and the fathers. After passing A.M., he began to give private lectures in those branches and in theolog. Thence he went to Marburg, where the teachings of Winckelmannn and Mentzer deeply impressed him. After lecturing on theology at Jena, he accepted the superintendency of Heldburg, offered him by Casimir, duke of Coburg, in 1606. Declining two calls to Jena in 1610 and 1611 and one to Wittenberg in 1613, he finally accepted the seniorate of the faculty of Jena, at the command of George I, elector of Saxony, in 1615. Here he devoted his great talents industriously to his duties to the university, the Church, and the state. He held the first place in the ecclesiastical conferences at Jena, 1621; Leipsic, 1624 and 1630; and was consulted by princes both in ecclesiastical and secular matters. He died August 20, 1637. Gerhard's great points of excellence as a dogmatic writer are comprehensiveness of plan, thoroughness of the treatment of topics, and perspicuity of style. The Loci Communes Theologici has not only been a standard of Lutheran theology for two centuries, but has also been greatly valued by Roman Catholic and Reformed theologians.
The exegetical writings of Gerhard are also of great value, the most important being Comment. in Harmoniam hist. evang. de Passione et Resurrectione Christi (1617, 4to), a continuation of the commentaries of Chemnitz and Lyser, and published with them (Hamburg, 1652, 3 volumes, fol.). It is specially valuable for its patristic learning. Posthumously appeared his Comm. in Genesin (1637, 4to); Comm. in Deuteronomium (1638, 4to); in 1 and 2 Timothy (1643); in 1 and 2 Peter (1641); ad Coloss. (1660, 4to); ad Romanos (1666, 4to). He also published De Sacrae Script. Interpretatione (1610, 4to): — Methodus Stud. Theol. (1620) — still valuable as a methodological work. In the sphere of dogmatic theology Gerhard has made his name immortal by two great works; the first is Doctrina catholica et evangelica, quam ecclesie Augustanae confessioni addictae profitentur ex Romano-catholicorum scriptorum suffragiis confirmata (1634, 3 volumes), a work which many theologians consider the best of Gerhard's writings. The other great work is Loci Theologici, cum pro adstruenda veritate, tum pro destruenda quorumvis contradicentium falsitate, which he begun in Heldburg when only twenty-seven years of age, and of which he celebrated the completion (ninth volume) at Jena in 1629 (first edit. Jena, 1610-1625, 9 volumes; frequently reprinted; one of the best editions is that by Cotta, Tüb. 1762- 1789, 22 volumes, 4to, the two last volumes containing index by G.H. Muller; a new edition was begun by Dr. Preuss, Berlin, 1867 sq.). That part of the Loci which treats of God and of the person of Christ was developed more fully in his work published in 1625, under the title Exegesis sere uberior explicatio articulorum, etc. The value of the Loci Theologici in comparison with the predecessors of Gerhard in the Lutheran Church, especially with Hutter and with his successors, especially with Calov and Quenstedt, is ably treated by Gass in his Geschichte der protest. Dogmat. 1:261.
The practical writings of Gerhard are full of the spirit of Christian love and devotion. He was, indeed, charged by the cold dogmatists of the time with pietism and mysticism. Among them are Meditationes Sacrae ad versam pietatem excitacndam etc. (Jena, 1606): — Schola Pietatis, d. 1. christl. Unterrichtung z. Gottseligkeit (Jena, 1622-23,12 volumes): — 52 Heilige Betrachtungqen. These have been frequently reprinted; the Meditationes has passed through scores of editions, and has been translated into English and often reprinted (latest, Lond. 1841, 12mo). For a list of all his writings, see Fischer, Vita Joannis Gerhardi (Lips. 1723); see also Herzog, Real- Encyklopidie, 5:40; Gieseler, Church History (ed. Smith), 4:574.