In 1584, Marcus Friedrich Wendelin was born in Sandhausen, Germany, not far from Heidelberg. His father was a Gospel Minister, and invested in his son’s education. At the age of eleven, he was enrolled in the Heidelberg Pedagogium, but he did not initially take to the rigorous discipline of study. It took time, but eventually Wendelin proved a model of scholarly zeal and ability.
He continued his studies at the University of Heidelberg: in philosophy, focusing on Ramism; in theology, studying under the illustrious David Pareus. Wendelin graduated in 1607, well grounded in the Reformed faith, and well prepared for a life of scholarship
After graduation, he worked for a time as a private tutor, until his appointment as Rector of the Illustrious Gymnasium of Zerbst, Germany, in 1612. There Wendelin spent the rest of his life in the administration of the school and scholarly pursuits, studying, writing, and teaching. Living on the frontier between the Reformed and Lutheran Churches, the polemical context urged him toward remarkable precision in theological statement, a precision demonstrated in his Systemate Maiori (a complete systematic theology presented in syllogistic form), and in his Collatione Doctrinæ Christianæ Reformatorum et Lutheranorum. Although Wendelin enjoyed regard and esteem on both sides of the Confessional divide, his critique of Lutheran doctrine drew mighty opponents into the field: including Christoph Frank of Kiel (Exercitationibus Anti-Wendelinis) and the great John Gerhard (Collegio Antiwendelino).
Although Wendelin received invitations to teach at other, more prestigious institutions, he declined, choosing to remain at Zerbst. There he entered into his rest in 1652.
Wendelin’s Christinæ Theologiæ Libri Duo (Christian Theology) differs from his Systemate Maiori in at least three ways: 1. The former is positive, rather than polemical. 2. It is briefer. 3. And, finally, although Wendelin’s careful logical method is evident throughout, it is less rigorously syllogistic. Consequently, Christian Theology is more suitable as an introductory text.
It is hoped that Wendelin’s Christian Theology might now be a blessing to Christians in English-speaking lands, and it was to European Christians in times past.
 David Pareus (1548-1622) was a German Calvinist, serving the Reformed Church as a minister, churchman, and professor. He wrote a commentary on the whole Bible, and it was held in high estimation among the Reformed. His Commentarius in Epistolam ad Romanos was burned publicly at Oxford and Cambridge in 1622 by order of the Privy Council of James I because of his comments on Romans 13, in which he upholds the right of resistance to tyranny.  Christoph Frank (1642-1704) was a German Lutheran, serving as Professor of Logic and Metaphysics (1665-1674), and later as Professor of New Testament (1674-1704), at Kiel.  John Gerhard (1582-1637) was an eminent Lutheran divine. He held the position of Professor of Divinity at Jena (1616), and he was four times the Rector of the same. He wrote copiously in exegetical, polemical, and dogmatic theology. His Loci communes theologici (1610-1622) was the largest Lutheran dogmatic text that had been produced to date.