[3] After Posen had become part of Poland, Ludwig moved with his wife in 1923 to Berlin, where he served as a policeman, and changed his family name to Kasner in 1930.

Kasner found a pastor's position with the Evangelical Church in Berlin-Brandenburg and the family moved to a rectory in the village of Quitzow near Perleberg.

[6] There, at the request of Albrecht Schönherr, then General Superintendent for the Sprengel (ecclesiastical region) Eberswalde, he took a development position in the religious education office.

Kasner was regarded as a religious leader and idealist who did not oppose the church governance or the policies of the Socialist party, unlike Schönherr and Hanfried Müller (members of the Weissensee Work Group (Weißenseer Arbeitskreis) standing in opposition to dominant national-conservative trend of Berlin-Brandenburg bishop Otto Dibelius).

All theologians were required as part of their education and training to spend some time as a vicar with their second theological examination in Templin.

The theological speakers were not handpicked to toe the line.Kasner took trips abroad as part of the National Front and was given the privilege of travelling to the West either by company car or private vehicle, which could be procured through Genex.

He was, alongside the Synod of the Berlin-Brandenburg Church, one of the earliest members of the Christian Democratic Union in East Germany.

Also negotiating alongside Kasner, Schnur, and de Maizière with the East German government from 1979 to 1988 and its state secretary for church affairs, Klaus Gysi.