Behind the portal made of red sandstone, a modern glass entrance opens up access to a richly appointed Rococo interior. The Augustinian hermits, a mendicant order established in Mainz since 1260, maintained their monastery on Augustinerstraße until the year 1802. Between 1768 and 1772, both the nave church and the monastery buildings were completely rebuilt. Since 1805, the bishop's seminary has been housed in the complex.
The extraordinary wealth of the church's furnishings is thanks to the generous support of patrons. The elector placed great importance on the fact that no simple "peasant church" was built in his residence city. The façade presents itself in the flowing style of the Franconian Baroque and is decorated with a representation of the crowning of Mary, created by the Mainz sculptor Nikolaus Binterim.
Inside, large, light-filled ceiling frescoes by the painter Johann Baptist Enderle from Donauwörth depict the life of the church father Augustine. The organ with the characteristic central window was built in 1773 by Johann Heinrich Stumm and is one of the few surviving instruments of this renowned organ builder family. Between the southern side altars, there is a linden wood sculpture from the year 1420 in a niche: Mary with the playful child Jesus. With its cheerful expression, it is regarded as an outstanding example of Gothic art of the so-called "soft style." The highly venerated image of grace was rescued from the burning Liebfrauenkirche in 1793. An iconographic peculiarity is finally revealed in the high altar: At the death of Christ, God the Father symbolically has a putto tear the "debt certificate of humanity."
