The upper or main church, designed by Hans Schwippert, benefits from a pleasing symmetry around the principal axis that connects the organ and altar. Restraint is the watchword here with the emphasis on a limited number of design elements that combine in an appealing ensemble.
Schwippert made the church appear concentrated towards the altar by the meaning of the word using concentric circles as a design element repeating in the floor, arrangment of benches and so on.
The church windows are designed by Prof. Anton Wendling, Aachen.
The dark marble of floor, altar and cathedra comes from Kapfenberg in Thuringia (Thüringen). The bordering between lower and upper church made out of bronze and crystal class fins were created by Prof. Fritz Kühn, Berlin.
Altar cross and tabernacle
The goldsmiths Fritz Schwerdt and Hubertus Förster (Aachen) created the gold-plated altar cross decorated with red enamel. The corpus is made of a single peace of ivory.
The same two goldsmiths are also the creators of the also gold-plated tabernacle which is at the outside decorated with nacre, cabochoned rock crystals and with enamel fittings and silver rosettes at the inside.
Statue of St. Peter
The statue of St.Peter was created around the year 1340 an can be attached to the Sienese School. The gift from Pope John Paul II in 1980 marks the fiftieth anniversary of the establishment of the Berlin diocese – St. Peter is the first patron of the diocese.
Statue of the Virgin Mary
The late-Gothic Marian figure (around 1500) was a gift of Cardinal Julius Döpfner on the occasion of the reconsecration of the cathedral in 1963 after its reconstruction. The statue is embraced by a contemporary aureola made of arenite by Hubert Elsässer, Gröbenzell.
Cardinal Döpfner had served as Bishop of Berlin from 1957 to 1961 when he was appointed Archbishop of Munic and Freising.
Three impressive tapestries give a very distinctive demeanour to the interior of the cathedral. All three share the motif of the heavenly Jerusalem - only one is set up at a time.
The grey-green Gobelin by Grete Reichardt of Erfurt in Thuringia was hand woven in 1963. It depicts a stylisation of a city with the names of the apostles inscribed on foundation stones. God is represented by the Tree of Life and a lamb features as a symbol of Christ.
The other two tapestries pick up themes from the Book of Revelation (the Apocalypse).
The second one was made by Anton Wendling before 1965 in a quilt-like technique ('Applikationstechnik'). Wendlig creates a festive, colorful geometric composition showing a high-ranking idealistic architecture whilst putting the symbol-rich language of the Book of Revelation into the center of attention.
The threepart woven carpet made by Else Bechtele, Munich, was build in cooperation with the 'Nürnberger Gobelinmanufaktur' in the years 1979 to 1981.
It picks up the 4th chapter of the Book of Revelation and shows God with a blessing hand as 'the one sitting on the throne' and the one 'beeing amongst us' at the same time.
The Stations of the Cross
The Stations of the Cross in the lower church recall Christ’s journey to Calvary.
Created in 1961 the graphics represent the last major work of Joseph Hegenbarth of Dresden, who died in 1962. Today the graphics are replaced by copies.