One of National Socialism's primary goals was to create "a true national community". To this end, all independent institutions and associations were either to be brought into line or dissolved. While the Catholic Church had been "quietened down" by the conclusion of a concordat in July 1933, the Protestant Church was to be brought into line.

Two lawyers from Wiesbaden were responsible for pursuing this goal in Berlin: Wilhelm Stuckart, State Secretary in the Prussian Ministry of Culture, and August Jäger, the former Wiesbaden District Court Judge. Both were initially successful. With Hitler's personal support, they succeeded in seizing power in most of the Protestant regional churches. In a nationwide "church election" on July 22, 1933, the majority of church councils and synods were filled with National Socialists and "German Christians", the church party supporters of the NSDAP.

As the Nazi state was extremely church-friendly at the time, there was hardly any resistance. This only changed when the synods adopted the "Aryan paragraph" from the Reich Law on the Restoration of the Professional Civil Service of 7 April 1933, according to which only "purely Aryan" pastors - without a Jewish parent or grandparent - were allowed to officiate in the church. Only one pastor, Karl Amborn (1890-1952) from Braubach, objected to this decision at the "Brauner Landeskirchentag" of the Evangelical Church in Nassau on September 12, 1933 in Wiesbaden, but 60 pastors had already signed the "Pfarrernotbund" pledge the day before in Berlin. In it, they promised to protect the church against outside influence and to stand up for their fellow ministers affected by the synodal resolutions.

In the following years, the Pfarrernotbund developed into the backbone of the church's opposition; its leader was Pastor Martin Niemöller. Within a few weeks, several thousand pastors joined, including some pastors in Wiesbaden. In contrast, the associations of German Christians in Nassau had completely disbanded by the end of 1933. The fact that the regional church congress, chaired by August Jäger, had forced the Nassau regional bishop August Kortheuer out of office in an unworthy manner also contributed to this.

The most important decision of the regional church congress was the unification of the Evangelical Church of Nassau with the two regional churches of Hesse-Darmstadt and Frankfurt am Main. Hesse-Kassel canceled the unification at the last moment. Hesse-Darmstadt claimed the leading office in the new regional church, which was given the name Nassau-Hesse. At the first joint synod, the Hessian prelate Wilhelm Diehl (1871-1944) was proposed, as was the 36-year-old pastor of the Wiesbaden Marktkirche, Ernst Ludwig Dietrich. This name triggered fierce protests in all three regional churches. Nevertheless, Dietrich was appointed Bishop of Nassau-Hesse by Reich Bishop Ludwig Müller on February 8, 1934. He exercised his office with prohibitions and punishments and was strongly supported in his administration by Berlin and the regional party leadership.

In the first half of 1934, the church opposition had grown considerably. Since the confessional synod in Barmen (29-31 May 1934), confessional communities had been formed everywhere, including in Nassau-Hesse, in which not only the opposing pastors were united, but also parishioners and entire congregations. At the confessional synod in Dahlem in October 1934, the opposition finally officially declared its disobedience to the unlawful church regime and called on the congregations to submit to the confessional synod instead. In Nassau-Hesse, too, a large number of pastors and congregations declared their rejection of the Reich and state church governments. A regional brotherhood council was founded, which acted as a regional emergency church leadership for the confessing congregations. The church policy of the Nazi government had failed.

Hitler canceled the grandly announced reception of the regional bishops and the ceremonial swearing-in of the Reich bishop; August Jäger, the main protagonist of the Gleichschaltung, was relieved of all his offices. The attempt to force the regional churches into a unified Reich Church had worked for some, such as in Nassau Hesse, at the official level, but the Protestant Church had broken apart. The extent to which the Reich government was affected was shown by the "Wiesbaden Speech" given by Reich Interior Minister Wilhelm Frick (1877-1946) on December 7, 1934, in which he claimed that "anti-state and traitorous elements" were gathering in the church opposition and decried the disputes as a "pastors' squabble".

Alongside others, Stuckart presented his concept for a future church policy. Hitler appointed him State Secretary in the Reich Ministry of the Interior. According to Stuckart's proposal, the Reich government was to refrain from implementing the Führer principle in the church, but the church administration was to be more closely controlled. A new Ministry for Church Affairs was created under the leadership of Hanns Kerrl (1887-1941). He set up a Reich Church Committee with more or less neutral personalities as well as regional church committees in the "destroyed churches", which included Nassau-Hesse. Bishop Dietrich was forced to relinquish his powers; he only retained his title. The regional church committee attempted to mitigate some of the punitive measures from Dietrich's time. This second phase of the conflict brought only an outward pacification. The Confessing Church did not recognize the orders of the church committees appointed by the state.

The third phase of the conflict began in Nassau-Hesse in mid-1937 with a ministerial order: the previous head of the regional church office, President Paul Kipper, was appointed sole head of the regional church. The former Wiesbaden district court judge Kipper had become head of the church administration in Darmstadt in 1934 and had adapted to the Nazi system.

However, as National Socialism was recognized as hostile to the churches and Christianity during this time, the conflicts continued. Even during the war, the state repression against the church by no means abated. Pastors, including clergymen from Nassau, were sent to concentration camps. Religious instruction was denied to the churches; church congregations were deprived of their kindergartens; baptisms were no longer allowed to be performed in hospitals; pastors were only allowed to visit the sick in hospitals if they were asked to do so. However, the most radical measure in 1939 was the segregation of "racially Jewish Christians" not only from the congregations, but from the Protestant church in general. President Kipper had co-signed the corresponding appeal. The Landesbruderrat protested vehemently - without success.

Since January 1939, the various church groups had merged to form the "Nassau-Hessen Unification Organization". The leaders were Friedrich Müller (1879-1947) from Darmstadt as the representative of the "Mitte", a group of undecideds that had newly formed, Pastor Karl Veidt for the Confessing Church and Bishop Dietrich as the representative of the "Landeskirchliche", as the group called itself under his leadership. Dietrich had publicly distanced himself from his earlier path and regretted all the measures that had severely affected his fellow ministers. However, even the unification work was unable to steer the Nazi course of the church authorities in a different direction.

The struggle over the question of what influence the state should have on the life of the churches had resulted in a kind of resistance to state policy, which many of those involved here had not originally wanted. This led to the Western Allies recognizing the Confessing Church as a resistance group after the collapse, even though it had not actually wanted to be one.