One problem with associating an English gloss or two with a Greek word and then proceeding to “read” a text by doing a decode-o-rama followed quickly by a de-yoda-ification (I speak as one with deep, intimate knowledge of this mystical practice) is that you end up throwing context to the wind if you’re not careful, and many times even if you think you are being careful.
After some brief examination of lexicons and dictionaries, one might think it is reasonable to generally associate the gloss “lust” with the Greek verb επιθυμεω. After all, that seems to be the sense one runs into in the NT. If not “lust”, then perhaps “strong desire” or something else of such ilk, with a nod to being general and non-specific, but really knowing that “desire” has to do with that of the sexual sort; and if not that then at least the desire of something sinful or wrong. Oh, there might be exceptions (1Ti 3.1 talks of “desiring a good work”) but the word (and cognate group, especially the noun form) really has to do with sexual lust … at least, that’s the approach that I’ve heard and have seen, and that’s the word-study trap that’s easy to fall into.
Here’s the problem: Look up επιθυμεω in BDAG, and check out the citations for sense 1 (“to have a strong desire to do or secure something, ‘desire’, ‘long for’”) and compare those to sense 2, the “lust” sense. Sense 1 has many more citations and a broader range of cited material. But even in sense 1, many examples seem to be negative (“desiring” unwholesome things). Then, assuming you’re being diligent and looking up citations because you really want to understand and you’re not just cherry-picking to bolster your pre-conceived notions, you run into Poly 1.3:
“Even without seeing him, you believe in him with an inexpressible and glorious joy that many long to experience. For you know that you have been saved by a gracious gift—not from works but by the will of God through Jesus Christ” (Ehrman).
The bold bit is translated as “which many desire to experience” by Holmes. Lake has “many desire to come”; Lightfoot has “many desire to enter in”. The word translated “desire” or “long to” is … yep, you guessed it … επιθυμεω. There is nothing about “lusting” in a sexual sense here. The context here has to do with “longing to” experience the joy one experiences as a result of belief and trust in Christ. The joy experienced by the Philippians is “strongly desired” to be experienced by others.
You don’t even need to go to the Apostolic Fathers for the non-lusty sort of επιθυμεω; some responsible reading of the BDAG definition gets you there only with NT citations. 1Ti 3.1 and Mt 13.17 are great examples, but the killer to the επιθυμεω-means-sexual-lust argument has got to be Lk 22.15, where Jesus “strongly desires” to eat the passover with his disciples.
Bottom line: It’s a chicken-and-egg proposition, just like reading in English. You only know what επιθυμεω means by reading lots of stuff and building up a concept of what επιθυμεω means. Lexicons like BDAG help, but it’s easy to be myopic in word-study land where even though a “word” is being studied, it is usually prompted by a particular instance in a particular context one wants to understand. It is this local context that is important; not the word. Context is how the author constrains the variables. If one says “lust after her” or “desire her”, it’s easy. In Poly 1.3, is essentially telling the Philippians that “there are many who really want to experience that joy you’re experiencing”. In Poly 1.3, Mt 13.17 and Lk 22.15, the formula is επιθυμεω + infinitive verb where the infinitive verb (and its associated items) help one determine the nature of the “desire”. In the same way the object of επιθυμεω when not used with an infinitive (thus typically a genitive or accusative, as we see in 1Ti 3.1; check BDAG) help dial in this constraint … not anything innate in the word itself. Be very careful what local context you import into the definition of a word to apply elsewhere (go back and re-read your Exegetical Fallacies), and be even more careful about how glosses perpetuate false conceptions of word meaning.
No matter what, when your understanding of επιθυμεω is limited to one or two-word English glosses (“lust, strong desire”) your understanding of the Greek text will be similarly limited. So make it a goal to read and work through lots and lots and lots of text. I can’t tell you how helpful this has been to me! Then when you hit επιθυμεω, you’ll think in your head “επιθυμεω” and not “lust, strong desire”. And that’s a step in the right direction.