Hildebrandt subsequently served for the Evangelical Church of the old-Prussian Union his probationary time (Vikariat) in Dobrilugk and at the  in Schöneberg (a locality of Berlin), and his first posting as an assistant pastor in Kleinmachnow; he was ordained as a pastor in Berlin on June 18, 1933.
After completing his probationary period, Hildebrandt worked in Dobrilugk and Schöneberg (a neighborhood of Berlin), before being assigned to Kleinmachnow as an assistant pastor. He was ordained as a pastor in Berlin on June 18, 1933.