Have you ever considered using digitized newspaper websites to learn more about your ancestor's church? Yes, there are religious newspapers but I'm referring to your ancestor's hometown newspaper.
All types of newspaper articles can refer to your ancestor's church. Like the screenshot below, small notices about activities at the church may be mentioned. But don't forget other types of articles that would announce events and report on members.
This page from the Evansville Argus, shown below, is from 9 December 1939. The Argus was an African- American newspaper published from 1938-1945. In our Churches is a column that featured churches and their activities. A nice "history" for those with Evansville (Indiana) ancestors.
A nice aside is that there are member names in these church snippets.
There are many websites to find newspapers online. Subscription websites like GenealogyBank and Newspaper Archives is a good start. Don't forget other genealogy subscription websites as well including Ancestry.com and WorldVitalRecords. States have newspaper digitization projects including Utah, California, and Colorado. In some cases, newspapers can be part of an university or archive special collection or even a digital collection. In this case, this newspaper collection is available on the website for the University of Southern Indiana, David L. Rice Library University Archive and Special Collection.