The interior is arranged with warm, bright colors and their transparent simplicity is a clear contrast to the church's appearance from the outside.

The entire interior design, including the windows, the altar, and the organ were designed by the painter and sculptor W. Gies from Cologne.

The artist Gies, who "normally paints pictures who nobody has ordered", accepted the commission under the conditions that he has for the most part the freedom to plan as he desires. Several different organ builders submitted designs for the interior, with it's clear abstract symbols and use of carefully selected materials.

For Gies, these were all too conventional: "They were the usual styles, somewhere between neogothic and modern refrigerator."