I've found that access to church records in areas now within the borders of Germany varies widely according to location and time period.
I've had luck with regard to my Catholic German ancestors in the diocese of Speyer in the Rheinland Palintate. Coverage is by no means complete, but a lot of records are available. But if I move over a few towns or villages, it may not be as good.
I've been less successful with my protestant German ancestors from areas in the north of what was East Germany and in areas that are now Poland. A few records seems to be online, but most are not. More of these seemed to have been destroyed in wars.
My best results at finding what is available has come by doing Google searches on regional geographic names and terms like church records.
Some are on Family Search. A few are on Ancestry. More, especially Lutheran ones in German, are on Archion.de, which requires a fee.
There is an article at https://www.familytreemagazine.com/premium/german-church-records-guide/ with links to several sites to try and some advice on how to make the best effort at finding what you need.
Personally, I'm concentrating on my Catholic German ancestors and church records found on Family Search for three reasons: 1) I read Latin a whole lot better than German, so its going a lot faster and I'm finding more information I can pull out and 2) Family search has a better search engine from my point of view for those records which are indexed and a surprising number of the Catholic ones filmed by LDS are indexed and 3) In general, for my eyes, both the images and the tools for tweaking the images on the Family Search viewer for digital images of microfilm seem easier to bring into better contrast and focus for me than some of the viewers I've worked with on other sites.
Expect lots of holes and celebrate when you find a relevant record.