If you are a Christian, you’ve probably heard of, or used Monergism.com. They have been publishing public domain, free to read, Christian e-books, for years, as well as some contemporary works, and some for purchase. I have downloaded, and benefited from their work personally, and encourage you to check them out. They are also in need of funds to continue their work. Please consider giving to them. They are a valuable resource, and I’d hate to see them go.