St. John's Church, one of the two Catholic parish churches in Rüthen, is a three-nave hall church built in neo-Gothic style in 1872-74. The tower and the antechapel were newly built in 1737. In the chapel there is the oldest work of art in Rüthen, the statue "Maria vom Stein", created from the local green sandstone, probably shortly after the foundation of the town of Rüthen.
The neo-Gothic nave was built with a choir with 5/8 end and choir side chapels from 1871 to 1874 according to plans by Arnold Güldenpfennig. The choir is decorated with elaborate mounts and stained glass from the time of construction. In the three-bay nave, ribbed vaults rest on slender round pillars. The side aisles have rhombus vaults. The baroque west tower, built in 1737, faces west. It was built of hammered green sandstone with corner ashlars. The rib-vaulted tower hall was opened to the plain hall of the chapel and to the church. At the same time, the neo-Baroque Marienkapelle was built in front of the tower. It is a flat-roofed hall with richly formed window frames. In the cape The neo-Gothic nave was built with a choir with 5/8 end and choir side chapels from 1871 to 1874 according to plans by Arnold Güldenpfennig. The choir is decorated with elaborate mounts and stained glass from the time of construction. In the three-bay nave, ribbed vaults rest on slender round pillars. The side aisles have rhombus vaults. The baroque west tower, built in 1737, faces west. It was built of hammered green sandstone with corner ashlars. The rib-vaulted tower hall was opened to the plain hall of the chapel and to the church. At the same time, the neo-Baroque Marienkapelle was built in front of the tower. It is a flat-roofed hall with richly designed window frames.
The chapel houses the image of Mary of the Stone.
The organ with pneumatic cone chests was installed in 1894 by Franz Eggert from Paderborn. The front pipes were confiscated for war purposes in 1917 and replaced in 1920. Siegfried Sauer from Ottbergen electrified the action in 1978 and installed new single bellows. In 2005 he restored the organ extensively. Except for changes in the names of the stops, the sound system, the chests, and the prospect have been preserved in their original condition.