Dictionary.com

1. the study of literary texts and of written records, the establishment of their authenti-city and their original form, and the determination of their meaning.
2. (especially in older use) linguistics, especially historical and comparative linguistics.
3. Obsolete. the love of learning and literature.

Etymonline.com

late 14c., “love of learning,” from Latin philologia “love of learning, love of letters, love of study, literary culture,” from Greek philologia “love of discussion, learning, and literature; studiousness,” from philo– “loving” (see philo-) + logos “word, speech” (see Logos).

Meaning “science of language” is first attested 1716 (philologue “linguist” is from 1590s; philologer “linguistic scholar” is from 1650s); this confusing secondary sense has not been popular in the U.S., where linguistics is preferred. Related: Philological.

Discussion/Explanation

I kinda would like to resurrect the original meaning of the term that has now become obsolete as is so clearly noted under the Dictionary.com entry. Even so…

The first definition under the Dictionary.com is what best fits for our purposes here. It is the area of study that is actively involved in authenticating ancient documents and this includes manuscripts of the Bible and particular books of the Bible. It is an area of study actively involved in all sorts of ancient/old documents, not just the Christian Bible.