To correct the prevailing ignorance in regard to Christian doctrine, Gesenius, in 1631, brought out his Kleine Katechismusschule, or " Brief Instruction as to how the Catechism Should be Taught to the Young and the Simple " (often reprinted).

Later, by order of Duke George and of the consistory, he issued an abridgment of this work under the title Kleine Catechismusfragen über den kleinen Catechismum Lutheri (1639 and manytimes republished).

Although Gesenius justified himself in a Grundliche Widerlegung (Lunenburg, 1641) and although his innocence was established through an investigation by impartial theologians, it must be admitted that, carried away by his zeal for a lively faith and for better knowledge, he allowed himself to wander from the straight path of Lutheran doctrine.

The strife concerning his Catechismusfragen was renewed in the eighteenth century, when King George I, in 1723, sought vainly to introduce Gesenius' catechism into the duchies of Bremen and Verden (cf.

In addition to the other services rendered by Gesenius to the cause of religious education, he published, in 1656, a manual of instruction in Biblical history, Biblische Historien Alten and Neuen Testaments.