After the death of his wife, Duke Christian decided to build a chapel at his Christiansburg Castle. The result was one of the most beautiful castle churches in Germany. The Baroque splendor of the interior was created by the Italian masters Bartolomeo Quadri and Giovanni Caroveri. The organ is the work of the Leipzig master Christoph Donath.

The castle church is open for viewing and worship and is used for concerts and weddings. The church is considered the most magnificent baroque church in Thuringia. It impresses with its two-storey organ in the chancel.