§ 169.1. =The German Reformed Church.=--The Brandenburg dynasty made unwearied efforts to effect a =union= between the Lutheran and Reformed churches throughout their territories (§ 154, 4). Frederick I. (III.) instituted for this purpose in A.D. 1703 a _collegium caritativum_, under the presidency of the Reformed court preacher Ursinus (ranked as bishop, that he might officiate at the royal coronation), in which also, on the side of the Reformed, Jablonsky, formerly a Moravian bishop, and, on the part of the Lutherans, the cathedral preacher Winkler of Magdeburg and Lüttke, provost of Cologne-on-the-Spree, took part. Spener, who wanted not a made union but one which he himself was making, gave expression to his opinion, and soon passed over. Lüttke after a few _sederunts_ withdrew, and when Winkler in A.D. 1703 published a plan of union, _Arcanum regium_, which the Lutheran church merely submitted for the approval of the Reformed king, such a storm of opposition arose against the project, that it had to be abandoned. In the following year the king took up the matter again in another way. Jablonsky engaged in negotiations with England for the introduction of the Anglican episcopal system into Prussia, in order by it to build a bridge for the union with Lutheranism. But even this plan failed, in consequence of the succession of Frederick William I. in A.D. 1713, whose shrewd sense strenuously opposed it.--The vacillating statements of the _Confessio Sigismundi_ (§ 154, 3) regarding =predestination= made it possible for the Brandenburg Reformed theologians to understand it as teaching the doctrine of particular as well as universal grace, and so to make it correspond with Brandenburg Reformed orthodoxy. The rector of the Joachimsthal Gymnasium in Berlin, Paul Volkmann, in A.D. 1712, interpreted it as teaching universal grace, and so in his _Theses theologicæ_ he constructed a system of theology, in which the divine foreknowledge of the result, as the reconciling middle term between the particularism and universalism of the call, was set forth in a manner favourable to the latter. The controversy that was aroused over this, in which even Jablonsky argued for the more liberal view, while on the other side Barckhausen, Volkmann’s colleague, in his _Amica Collatio Doctrinæ de Gratia, quam vera ref. confitetur Ecclesia, cum Doctr. Volkmanni_, etc., came forward under the name of _Pacificus Verinus_ as his most determined opponent, was put a stop to in A.D. 1719 by an edict of Frederick William I., which enjoined silence on both parties, without any result having been reached.--One of the noblest mystics that ever lived was =Gerhard Tersteegen=, died A.D. 1769. He takes a high rank as a sacred poet. Anxious souls made pilgrimages to him from far and near for comfort, counsel, and refreshment. Though not exactly a