This is not so easy to define as it seems on a first view.
The protestant parish book of Laufenselden from 1692-1742 mentions Philipp Jacobus Hutstein to be born into the shepherd’s family of Johann Adam Hutstein and his wife Catharina Elisabeth in 1717 in Rettert.
But it does not necessarily mean that he had been a protestant. In fact the catholic and protestant inhabitants of this region lived door by door and often used the same church for their messes during their first centuries. The same applies for his father Johann Adam Hutstein: his marriage record is included in protestant church records of Dörsdorf in Hesse-Nassau, while some of his children occur in catholic records of this region. Sometimes the confession of persons can be estimated due to the corresponding marriage records only.
Additionally, many baptisms and funerals of catholic ones had been recorded in protestant church records. Sometimes they had been marked acc. their religion, often nothing else was written down.
This custom of using other religion’s church books can be observed in other regions of the Holy Roman Empire, too. E.g. children of Heinrich Christian Huthsteiner had been recorded in protestant church book of Meissen around the 1790s, beside they had been of catholic religion. It was law in Saxony that all births had to be recorded in the local main religion church book independent of their own faith. Similar happened in Bavaria, e.g. also a jewish child was recorded in a catholic church records book around 1630.