There are not only artistic treasures from past centuries to discover, but also craftsmanship of our days: The colorful painting of the interior was carried out by the Bavarian artist Karl Manninger and his student Hermenegild Peiker. The historical model was the frescoes of Joseph Appiani, destroyed in the war (created between 1752 and 1755). The extensive paintings depict the life and legends of the Apostle Peter. An original is still preserved behind the entrance.

The church was founded in 944 by Archbishop Friedrich of Lorraine. In 1748, court architect Johann Valentin Thomann built a new structure on the site of the demolished parish church of St. Marien. The original late Baroque elegance has been achieved in the historic restoration. Preserved are the richly decorated white-gold wooden pulpit from the master workshop of Johann Förster and some lavishly adorned altars, including the crucifix altar by court sculptor Hans Backoffen from the 16th century. The celebration altar was created in 1989 by the Palatine sculptor Gernot Rumpf – equipped with all sorts of "fishermen of men," wriggling in a bronze net. Later, an ambo and an Easter candle holder were added accordingly.