Strong's Concordance is a helpful tool that lists every Hebrew and Greek lemma (root word) present in the King James Bible (and it has been edited to conform to other translations as well, albeit usually with the original numbering system). Along with listing these, the tool also generally gives a 'gloss' for each word (some tools actually link Strong's Concordance to lexicons such as Thayer's Greek-English lexicon). The tool is popular because it is free on many Bible-related websites. With that said, I'd like to give some advice (and caution) to anyone who relies on this tool for original languages research in the biblical texts.
Using a concordance as a lexicon is problematic
It's like trying to hammer a nail in using a screwdriver—it's simply the wrong tool for the job.
A lexicon gives an inventory of all of the lexemes in a given language; Strong's Concordance is based only on a specific English translation (the KJV). Lexicons also function as dictionaries in that they define lexemes from the original language using English words that best capture their meaning, explaining any relevant grammatical features that impact their translation.
While Strong's Concordance gives a gloss for each lemma, this is not the main purpose of this tool and as such should not be used as a lexicon nor as a dictionary (a collection of glosses is rightly called a 'glossary'). Here are a few reasons why it is problematic to use Strong's Concordance as a lexicon:
Lexical ambiguity: Consider the following sentence: "She is looking for a match." Is the subject trying to light a candle or find a romantic partner? The 'gloss' definition here is ambiguous and gives us no help disambiguating the meaning in this context. Grammatical features should also be examined, which Strong's Concordance offers no help with.1
Nuances of meaning: Sometimes there is more than one meaning listed for a term (this is often the case for prepositions, but there are also verbs that change meaning depending on their voice and other grammatical features). Strong's Concordance offers no help when determining which (if any) gloss is most appropriate in context. Often knowledge of the original languages is required to determine what grammatical and contextual features are present in order to determine the correct gloss (if any). Also, authors can use the same word differently in various contexts.
The meaning of a lexeme is that intended by the author using it. Strong's Concordance often sheds little light on what this meaning is in context. Therefore, providing the meaning of a specific word in a given context on the basis of the Strong's Concordance is not a reliable claim, nor is challenging an existing English translation solely on the basis of a gloss from Strong's Concordance.
I often see folks try to determine the meaning of words in specific contexts using their root lemmata. The problem here is that etymology and the later meaning of a word are often orthogonal concepts. Here are some examples:
Etymology is not the primary tool for understanding the meaning of a word in a specific context, and it is often meaningless when making such a determination.
What if Strong's Concordance is linked to a lexicon?
Several free online tools have linked Strong's Concordance entries to lexicon entries. Unfortunately, most of them use either Thayer's Greek-English Lexicon or Smith's Bible Dictionary for definitions, both of which were published prior to 1895. These resources are now considered to be obsolete by scholars (and contain much inaccurate information):
"...in 1895, Adolf Deissmann published his Bibelstudien - an innocently titled work that was to revolutionize the study of the NT. In this work (later translated into English under the title Bible Studies) Deissmann showed that the Greek of the NT was not a language invented by the Holy Spirit (Hermann Cremer had called it "Holy Ghost Greek," largely because 10 percent of its vocabulary had no secular parallels). Rather, Deissmann demonstrated that the bulk of NT vocabulary was to be found in the papyri.
The pragmatic effect of Deissmann's work was to render obsolete virtually all lexica and lexical commentaries written before the turn of the century. (Thayer's lexicon, published in 1886, was outdated shortly after it came off the press - yet, ironically, it is still relied on today by many NT students.)"2
Smith's Bible Dictionary was last updated in 1893 and is therefore subject to the same limitations as Thayer's lexicon.
These are so popular because their copyright expired and so they are generally free to use, but unfortunately they are now largely obsolete.
How to properly use Strong's Concordance
Strong's Concordance can be used effectively as an index of the occurrences of a lemma in the original languages of the biblical texts (at least in those manuscripts used by the King James Bible, which is a limitation of this tool, although some later revisions of it have addressed this to some extent). It's a great tool for identifying other occurrences of a lemma by using it's number (as this does not require that you can actually read the alphabet of the original language). This makes an original languages concordance accessible to those who cannot read those languages.
The gloss definition given by the concordance (or even a definition given by an outdated lexicon) can be helpful here in giving a general understanding of the lemma's meaning, but this should not be used as the sole source to justify the meaning or definition of the word in a specific textual context. However, it can help you see how the word has been translated in its other occurrences, which can give you a broader understanding of its semantic range and how it is generally interpreted in similar contexts (using multiple English Bible translations will help catch differences and nuances of meaning, which can lead to good questions about the meaning of lemmata in specific contexts, where someone versed in the original language can assist you in better understanding the passage). Pay close attention to differences in grammar, author, audience, genre, and historical setting as these can all influence the meaning of a lemma in a specific context.
Concluding warnings and encouragement
Strong's Concordance is an index of occurrences of a lemma in the original language of the biblical texts, it is not a lexicon/dictionary (and thus is not a reliable source for the meaning of a lexeme in a specific context). However, this tool is a great resource for those who wish to better understand how a lemma has been understood by English Bible translators in its other occurrences, and biblical study conducted using Strong's Concordance can provide the impetus for many good questions about the biblical texts where someone trained in the original language(s) can assist you further with understanding the meaning of a lexeme in a specific text of interest (perhaps your interest in these questions will even drive you to study the original languages for yourself!).
This article has been adapted from one of my posts on the Biblical Hermeneutics Meta Stack Exchange site. Stack Exchange user contributions are licensed under cc by-sa 3.0 with attribution required.This article was heavily influenced by a series of blog posts that address this superbly on the Armchair Theology site.
1 I took a course on the Bible during my undergraduate program where a classmate argued that the woman in Luke 8:43-44 had a sexually transmitted disease (STD) on the basis of the King James Version translation and corresponding Strong's Concordance gloss. The relevant text in the KJV translation reads, "And a woman having an issue of blood twelve years ... Came behind him, and touched the border of his garment: and immediately her issue of blood stanched." She understood 'issue' to refer to a 'problem in' the woman's blood, rather than as (the correct understanding of the Greek text which is) 'the flowing or coming out' of blood from the woman's body, i.e. hemorrhaging (likely a medical condition related to menstruation).
2 Daniel B. Wallace. The Basics of New Testament Syntax: An Intermediate Greek Grammar. Zondervan, 2000, p. 21.