I found this on the internet which may help
Birth/ Baptismal Names
Two names were usually given to a child at birth or baptism. In Germany, the first name - what we often refer to as a given name - was a spiritual name, usually to honor a favorite saint. The spiritual name was often used repeatedly in families. The second name - what we now would refer to as a middle name - was a secular or call name, and was the name by which the person was known. One of the most common and heavily used saint's names for males was "Johann" (with no "s"), and for females, "Johanna" or "Anna". Thus, in a hypothetical German family, we might see the male children named:
Johann Heinrich Riepe
Johann Hermann Riepe
Johann Friedrich Riepe
Respectively, these children would be known as Heinrich (Henry), Hermann, and Friedrich (Fred).
For girls, we may see: Anna Maria Riepe
Anna Catherine Riepe
Anna Louise Riepe
Respectively, these children would be known as Maria (Mary), Catherine, and Louise.
Again, these patterns were not always carved in stone, but it is helpful to understand the basic custom when researching German families. You may know your ancestor was called Henry, and thus assume his name was Henry Something Riepe, when in fact, his name was Johann Heinrich Riepe. If his parents were called William and Catherine, their full names may have been Johann William and Anna Catherine