Theodor Undereyck (born 15 June 1635 in

Duisburg Duisburg () is a city in the Ruhr metropolitan area of the western German state of North Rhine-Westphalia. Lying on the confluence of the Rhine and the Ruhr rivers in the center of the Rhine-Ruhr Region, Duisburg is the 5th largest city in Nor ...

, died 1 January 1693 in

Bremen Bremen (Low German also: ''Breem'' or ''Bräm''), officially the City Municipality of Bremen (german: Stadtgemeinde Bremen, ), is the capital of the German state Free Hanseatic City of Bremen (''Freie Hansestadt Bremen''), a two-city-state consis ...

) was a

Protestant Protestantism is a Christian denomination, branch of Christianity that follows the theological tenets of the Reformation, Protestant Reformation, a movement that began seeking to reform the Catholic Church from within in the 16th century agai ...

pastor A pastor (abbreviated as "Pr" or "Ptr" , or "Ps" ) is the leader of a Christian congregation who also gives advice and counsel to people from the community or congregation. In Lutheranism, Catholicism, Eastern Orthodoxy, Oriental Orthodoxy and ...

, spiritual writer and pioneer of

pietism Pietism (), also known as Pietistic Lutheranism, is a movement within Lutheranism that combines its emphasis on biblical doctrine with an emphasis on individual piety and living a holy Christian life, including a social concern for the needy and ...

in the

German Reformed Church German(s) may refer to: * Germany (of or related to) ** Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

. Theodor Undereyck was born in 1635, the son of businessman Gerhard Undereyck and his wife Sara, née Salanger. After the death of his parents in 1636 by the plague, he grew up as an orphan in the house of his uncle Johann Undereyck in Alstaden. From 1653 to 1658 he studied

Protestant theology Protestantism is a branch of Christianity that follows the theological tenets of the Protestant Reformation, a movement that began seeking to reform the Catholic Church from within in the 16th century against what its followers perceived to b ...

Utrecht Utrecht ( , , ) is the List of cities in the Netherlands by province, fourth-largest city and a List of municipalities of the Netherlands, municipality of the Netherlands, capital and most populous city of the Provinces of the Netherlands, pro ...

, and

Leiden Leiden (; in English and archaic Dutch also Leyden) is a city and municipality in the province of South Holland, Netherlands. The municipality of Leiden has a population of 119,713, but the city forms one densely connected agglomeration wit ...

, under, among others, Gisbert Voetius and

Johannes Cocceius Johannes Cocceius (also Coccejus; ; 9 August 1603 – 5 November 1669) was a Dutch theologian born in Bremen. Life After studying at Hamburg and the University of Franeker, where Sixtinus Amama was one of his teachers, he became in 1630 profess ...

. His teachers were partly contrary to one another, but were orthodox Reformed theologians and representatives of continuing reformation. In particular Cocceius strongly influenced him in the direction of a federally theological thought, so that he was also considered one of the major catechists of Coccejanism. Voetius influenced him in the direction of a puritanical way of life and its emphasis on the importance of

Christian Christians () are people who follow or adhere to Christianity, a monotheistic Abrahamic religion based on the life and teachings of Jesus Christ. The words ''Christ'' and ''Christian'' derive from the Koine Greek title ''Christós'' (Χρι ...

conventicles A conventicle originally signified no more than an assembly, and was frequently used by ancient writers for a church. At a semantic level ''conventicle'' is only a good Latinized synonym of the Greek word church, and points to Jesus' promise in M ...

. From 1658 to 1659 Undereyck undertook a study trip to

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

, and

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

. In 1660, he became pastor of the Reformed church in

Mülheim an der Ruhr Mülheim, officially Mülheim an der Ruhr () and also described as ''"City on the River"'', is a city in North Rhine-Westphalia in Germany. It is located in the Ruhr Area between Duisburg, Essen, Oberhausen and Ratingen. It is home to many compan ...

. There in about 1661 he led one of the first

Pietist Pietism (), also known as Pietistic Lutheranism, is a movement within Lutheranism that combines its emphasis on biblical doctrine with an emphasis on individual piety and living a holy Christianity, Christian life, including a social concern for ...

conventicles in

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. From 1668 he was an associate court preacher in

Kassel Kassel (; in Germany, spelled Cassel until 1926) is a city on the Fulda River in northern Hesse, Germany. It is the administrative seat of the Regierungsbezirk Kassel and the district of the same name and had 201,048 inhabitants in December 2020 ...

to Landgravine Hedwig Sophie (1623–1683). In 1670 he became pastor at St. Martin's Church in Bremen and remained so until his death. Despite initial difficulties with the

clergy Clergy are formal leaders within established religions. Their roles and functions vary in different religious traditions, but usually involve presiding over specific rituals and teaching their religion's doctrines and practices. Some of the ter ...

, his ministry helped the breakthrough of

Pietism Pietism (), also known as Pietistic Lutheranism, is a movement within Lutheranism that combines its emphasis on biblical doctrine with an emphasis on individual piety and living a holy Christian life, including a social concern for the needy and ...

. His followers

Joachim Neander Joachim Neander (165031 May 1680) was a German Reformed (Calvinist) Church teacher, theologian and hymnwriter whose most famous hymn, '' Praise to the Lord, the Almighty, the King of Creation'' (german: Lobe den Herren, den mächtigen König d ...

and Cornelius de Hare (whose funeral sermon provides valuable biographical information on Undereyck) translated and continued Undereyck's work. Undereyck published 5 books, including two

catechisms A catechism (; from grc, κατηχέω, "to teach orally") is a summary or exposition of doctrine and serves as a learning introduction to the Sacraments traditionally used in catechesis, or Christian religious teaching of children and adult c ...

and a lay dogmatics, in which he conveyed the ideas of the

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

and

Dutch Dutch commonly refers to: * Something of, from, or related to the Netherlands * Dutch people () * Dutch language () Dutch may also refer to: Places * Dutch, West Virginia, a community in the United States * Pennsylvania Dutch Country People E ...

Reformed theology to German-speaking readers in edifying language. He dedicated his most extensive and sophisticated writing to the fight against emerging

atheism Atheism, in the broadest sense, is an absence of belief in the existence of deities. Less broadly, atheism is a rejection of the belief that any deities exist. In an even narrower sense, atheism is specifically the position that there no d ...

Age of Enlightenment The Age of Enlightenment or the Enlightenment; german: Aufklärung, "Enlightenment"; it, L'Illuminismo, "Enlightenment"; pl, Oświecenie, "Enlightenment"; pt, Iluminismo, "Enlightenment"; es, La Ilustración, "Enlightenment" was an intel ...

Works

* ''Christi Braut/ Unter den Töchtern zu Laodicaea/ Das ist/ Ein hochnöthiger Tractat/ In diesen letzten Tagen. Darinnen Die lebendige Krafft des seeligmachenden Glaubens von allen Schmach=Reden der in dieser Zeit Christ=scheinender Spötter/ nicht nur auß H. Schrifft: sondern auch auß gleichlautenden Zeugnüssen der darin gottseelig erfahrnen und Gott gelährten Männern gereiniget und verthädiget wird''. Hanau 1670; 2. Auflage Cassel 1697 * ''Wegweiser der Einfältigen zu den ersten Buchstaben des wahren Christentums, meistenteils nach der Ordnung der fünf Hauptstück Christlicher Religion''. Bremen 1676 * ''Hallelujah/ Das ist/ GOTT in dem Sünder verkläret. Oder Des sünders Wanderstab zur Erkäntnüs/ Geniessung/ und Verklärung GOTTes/ alß des höchsten Gutes''. Bremen 1678; 2. Auflage Herborn 1722; holländische Übers. 1684; dt. Auszug u.d.T: Eheliches Ja-Wort der gläubigen Seele. Hrsg. von Ch. Staehelin. Bern 1719; 2. Auflage Bern 1731 * ''Der Einfältige Christ/ Durch wahren Glauben mit Christo vereinigt/ und nach offt begangenem Mißbrauch/ zu dem rechten Gebrauch des H. Abendmahls/ daß Der Herr Jesus wird ..mit Feuerflammen Rache üben/ über die so GOtt nicht erkennen/ und nicht gehorsam sind dem Euangelio unsers HErrn Jesu Christi/ 2. Thesal. 1,8 ..'. Bremen 1681; 2. Auflage Eschwege 1700 * ''Der Närrische Atheist/ Entdeckt und seiner Thorheit überzeuget/ In Zwey Theilen In dem Ersten/ Als ein solcher/ der da wissentlich willens und vorsetzlich/ ihme selbst und anderen/ die Gedancken/ welche sie von GOtt haben/ nehmen wil. In dem Zweyten/ Als ein solcher/ der da unwissend und ungemerckt/ auch unter dem Schein des wahren Christenthums/ ohne GOtt in der Welt lebet''. Bremen 1689; 2. Auflage Bremen 1722; holländische Übersetzung Amsterdam 1702.

Bibliography

* Do-Hong Jou: ''Theodor Undereyck und die Anfänge des reformierten Pietismus''. Brockmeyer, Bochum 1994 * (with detailed bibliography).

References

{{DEFAULTSORT:Undereyck, Theodor German Calvinist and Reformed ministers 1635 births 1693 deaths People from Duisburg German theologians