Some church records are ephemera. They are not meant to preserved or archived. But despite that, we know that some ephemera does end up being archived or donated to special collections. Most likely, church bulletins listing names in your family are either going to be a home source or part of a special or manuscript collection.
A few weeks ago I went to a vintage paper fair. This turned out to be a great resource for finding materials that have genealogical value. One of the items I picked up was a church bulletin that not only had the usual listing of ministers, church staff and advertisements, but it also included a list of the names of people in their congregation serving in the military as of November 28, 1943.