The Greek New Testament, edited by Barbara Aland, Kurt Aland, Johannes Karavidopoulos, Carlo M. Martini, and Bruce Metzger, Fifth Revised Edition, 2015 because it is the standard Greek text including explanations of various readings.
A Greek-English Lexicon of the New Testament and other Early Christian Literature by Walter Bauer, Frederick Danker, W. Arndt, and F. Gingrich, Third Edition, 2000 because it is the best New Testament Greek lexicon, often citing all occurrences of a word and giving the breadth of its meaning.
A Greek-English Lexicon by Henry Liddell, Robert Scott, and Henry Jones, Ninth Edition with Supplement, 1996 because it provides the crucial context for Greek that preceded the Koine of the New Testament. By the way, Liddell is pronounced like Americans pronounce “little.”
Basics of Biblical Greek by William Mounce, 1993.
Biblia Hebraica Stuttgartensia 5th Reprint, 1997.
A Concise Hebrew and Aramaic Lexicon of the Old Testament edited by William L. Holliday, 1988 because it is both complete and concise.
Theological Wordbook of the Old Testament by R. Laird Harris, Gleason Archer, Jr., and Bruce K. Waltke, 2003 because it is the best in dissecting Hebrew words.
Not To Use:
Strong’s Exhaustive Concordance in any of its editions or versions and any online site or app based on Strong’s numbering system because it is based on an English translation of the Scriptures (KJV, NKJV, NIV, American Standard, etc.), is linked to dictionary definitions that are often confusing, overly simplistic, or just wrong, and has links to other Bible study resources that are not exegetically oriented or out of date (e.g. Thayer’s Greek Lexicon).