Kaulsdorf (then Caulstorp in the Electorate of Brandenburg) used to be a village of soccage farmers, with their dues to be delivered first to the Kalands Brethren confraternity in Bernau bei Berlin, as documented in a deed of donatio by Margrave Louis I of Brandenburg as of 1347, representing the oldest surviving record of Kaulsdorf.

Prince-Elector Joachim II Hector wanted to increase the number of canons at Berlin's Collegiate Church of Our Lady, the Holy Cross, the Ss.

Now Calvinist clergy had become the patrons of a Lutheran congregation in Kaulsdorf, since John Sigismund waived his regnal privilege to demand a conversion of his subjects (Cuius regio, eius religio).

In the course of the Thirty Years War (1618–1648) Lutheran Swedish troops under Gustavus II Adolphus and the Catholic Imperial Army under Wallenstein ravaged and plundered Kaulsdorf and its inhabitants in 1638.

[2] The new, longer nave received a flat ceiling above a circular ledge, carried by busts of angels (German: Engelsflüchte(n)).

[9] Prior to Grüber's appointment the few congregants in Kaulsdorf opposing the Nazi interference and adulteration of Protestantism did not organise as a group.

As the officially appointed pastor Grüber held the regular services in Jesus Church, preaching against the Cult of personality of Hitler, the armament of Germany, and anti-Semitism.

[11] The information about Grüber's appointment spread among the adherents of the Confessing Church in neighbouring congregations comprising the competent deanery Berlin Land I, such as Ahrensfelde, Biesdorf, Blumberg, Fredersdorf, Friedrichsfelde, Heinersdorf, Hohenschönhausen, Karlshorst, Klein-Schönebeck, Lichtenberg, Mahlsdorf, Marzahn, Neuenhagen, Petershagen, or Weißensee mostly without a local pastor supporting them.

In August 1935 his colleague Pastor Neumann from Köpenick preached instead of him, criticising the anti-Semitic policy of the German government, which earned him a denunciation by the presbytery.

[10] On the occasion of the Remilitarisation of the Rhineland in 1936 Hitler unconstitutionally and arbitrarily decreed a re-election of the Nazi puppet Reichstag for 29 March which was Palm Sunday, the traditional day Protestant congregations would celebrate the confirmations of the confirmands, who had grown to ecclesiastical adulthood.

The compromising Wilhelm Zoellner, leading the Protestant church bodies in Germany (1935–1937), regarded this an unfriendly act against Protestantism, but nevertheless obeyed and tried to delay the confirmations, asking a furlough for confirmands from the compulsory agricultural season labour of the Deutsche Arbeitsfront (DAF), starting right next Monday.

Thus only few pastors did not compromise in the end, but Grüber was one of the few (e.g., one out of 13 in Berlin) who held the confirmation services as usual, even though the Nazi government had announced this would not be without consequences.

[15] German Christian presbyters denounced Grüber again for his opposing attitudes at the March of Brandenburg provincial consistory and the Gestapo.

[16] The NSDAP local party leader (Ortsgruppenleiter) threatened to prompt Gruber's deportation to a concentration camp.

[17] The mainstream Nazi anti-Semitism considered the Jewry as a group of people bound by close, so-called genetic (blood) ties, to form a unit, which one could not join or secede from.

[18] So Bishop George Bell got his sister-in-law Laura Livingstone to run an office for the international relief commission in Berlin.

The well-organised Nazi squads killed several hundreds and 1,200 Jewish Berliners were deported to Sachsenhausen concentration camp.

Grüber was allowed to travel several times to the Netherlands and Great Britain in order to persuade the authorities there to grant visas for those persecuted in Germany.

Grüber learned about it by the Wehrmacht commander of Lublin and then protested to every higher ranking superior up to the then Prussian Minister-President Hermann Göring, who forbade further deportations from Prussia for the time being.

Now Grüber got himself a passport, with the help of Dietrich Bonhoeffer's brother-in-law Hans von Dohnanyi from the Abwehr, to visit the deported in the Gurs (concentration camp).

He was released from Dachau to his wife Margarete, née Vits, and their three children Ingeborg, Hans-Rolf, and Ernst-Hartmut in Kaulsdorf on 23 June 1943, after he signed an agreement not to help the persecuted any more.

Otto Dibelius, who had assumed the post-war leadership of the March of Brandenburg ecclesiastical province within the old-Prussian Church for the time being, appointed Grüber as one of the Nazi opposing pastors for the new leading bodies to be established.

[31] On 18 May 1945 Berlin's provisional city council, newly installed by the Soviet occupational power, had appointed Grüber as advisor for ecclesiastical affairs.

The square sacristy, a structure extending from the northern façade of the church, contains a cross-ribbed vaulted ceiling from the 15th century.

[2] The retable, created in 1656 and restored in 1958, is structured by columns and tuberous ornaments (German: Knorpelwerk) on the edges (Wangen) and surrounding portrait medaillons, which display Moses and John the Baptist.