Evangelische is the Lutheran Church in Germany. The Reformed Evangelische is a separate church but closely related. I went to www.telefonbuch.de and entered kirche (the German word for kirche) as the surname and 78733 as the place and there are currently no Reformed Churches in the postal code area. Perhaps the Reformed Church was closer to him in the U.S. In the town of Roetenberg, there are only Evangelische and Katholische. If you do not find him in the Evangelische Kirche then I would try the Katholische by correspondence. He was more likely to be Evangelische because of the area that he lived in and your family tradition. However, the other churches should be checked if you come up with a negative answer.