The Bas-Rhin Archives contain parish and civil registers for many of the towns in Bas-Rhin (free to access, but in order to view the records there, you need to accept the terms and conditions when prompted). Those records are considered reliable sources for the France Project.
I was unable to find a marriage record there for Hans George Angstadt and Eva Catharine Schafer in Obermodern or Zutzendorf around the 1725 time frame that you listed in your post, but I found a marriage record which may be theirs in the Gumbrechtshoffen Oberbronn parish records (Gumbrechtshoffen is where you had indicated their son John was born):
"Registres paroissiaux et documents d'état civil," images, des Archives départementales du Bas-Rhin (http://archives.bas-rhin.fr/detail-document/ETAT-CIVIL-C577-P2-R127992#visio/page:ETAT-CIVIL-C577-P2-R127992-625424 : accessed 20 August 2020), Périodes: 18e siècle, Marriage Hanß Georg Angstätt and Eva Catharina Schäfer, Feb 1726, image 297 of 331, p 580; Etat des fonds des Archives départementales du Bas-Rhin > Registres paroissiaux et d'état civil numérisés > Gumbrechtshoffen Oberbronn - Registres Paroissiaux (Avant 1793) - Paroisse protestante (Avant 1793) - Registre de baptêmes mariages sépultures 1702-1766 - 3 E 174/1.
Here's the info that I am able to abstract from the record (translated to English):
- Place: Gumbrechtshoffen
- Marriage date: Feb 1726
- Groom: Hanß Georg Angstätt, of Zützendorf
- Bride: Eva Catharina, daughter of deceased Hanß Adam Schäfer
If that's the correct marriage record for the individuals in question, you may also be able to find baptismal records for their children toward the front of that same record collection.