The Library of Congress Call Numbers for Religion are concentrated in the "B" section. Books are shelved by subject, so it can be useful to go to the general call number area you are interested in and browse the shelves in that area to locate books on your topic.
The "B" classification is divided into the following areas:
B-Philosophy
BF-Psychology
BJ-Ethics (see also R724-725-Medical Ethics, Bioethics)
BL-Religions, Mythology
BM-Judaism
BP-Islam, Baha'i, Theosophy
BR-Christianity-History
BR195 W6-History of the Early Church-Women
BS-The Bible
BS701-1830-Old Testament/Hebrew Bible (divided by book)
BS1901-2970-New Testament (divided by book)
BT-Christianity-Doctrinal Theology
BT1095-1255-Apologetics
BV-Christianity-Practical Theology
BV2000-3705-Missions
BX-Christian Denominations
BX6201-6495-Baptists
BX8000-8080-Lutherans
A more complete list can be found at The Library of Congress.
All of these call numbers are located on Wilson 1.
The library catalog is the place to locate scholarly books and ebooks in religious studies. To display only ebook results, make sure you select "available online" and "books" in the filters on the left side of the page.
You can also use an * and OR to expand your results, as shown below.