Therefore, Wallace tells us that the main function of the Greek article is "to nominalize something that would otherwise not be considered a concept," and "to conceptualize." In saying this, he basically means that an article by itself, or when it is packaged together with another word or phrase, will most often form an expression that can be treated as a noun — as a complete idea of something or someone, as a whole and fully defined concept in one's thoughts, as a view or picture of a total entity in the mind.
As Wallace explains, "... the article is able to turn just about any part of speech into a noun and, therefore, a concept. For example, [the adjective] 'poor' expresses a quality, but the addition of an article turns it into an entity, 'the poor.' It is this ability to conceptualize that seems to be the basic force of the article." Prepositional phrases, adjectives, infinitives and other phrases or expressions can all be turned into 'concepts,' into things, into nouns. English articles hold a bit of this ability, but they do not bear nearly as much of the broad and powerful ability of the Greek article.
So the power of the article is in its ability to conceptualize. Then, when it comes to actually using this core power, a great number of different functions can be performed. Of course, there are times when the Greek article functions much like an English definite article, indicating that the noun or substantive is a particular one, not just any one. However, more of its functions revolve around the broader role of identifying some person, persons, thing or things. Wallace tells us "it is used predominantly to stress the identity of an individual or class or quality." The Greek article creates an identifiable picture out of the word or words following it.
The purpose of the article added to plural hamartia is to personify those who have plural sins as sinners because they are the source for the acts. It's not to point to the acts, but to the source of the acts; and it's the singular inner quality and activity of the sin condition and the plurality of the effects of that condition that produce the outward plurality of actions.
But the articular is not to just identify the actions, but to attribute their source as the void in man's inner character failing to meet the standard of God's righteousness, thus inevitably resulting in conduct that also fails to meet the standard of God's righteousness.
The article serves to not merely identify actions, but to provide the conceptualization that those acts are the result of an inner condition. Economy of action is not incidental, but indicates an inability to exhibit and/or accomplish the righteousness of God by intention.
Yes, I know. And that's because you are an English thinker/speaker attempting to understand Greek noun constructs in arrears, and English has no grid for qualitative things. English quantifies. English has no equivalent for many nuances. English has no cases for nouns, either. Nouns in English are nebulous, but English speakers consider them very concrete because it's their baseline epistemology.
Language formats the sub-conscious and conscious mind in many ways. English formats nouns with no cases and no qualitative distinctions whatsoever. And due to its low-context nature, English doesn't depend on definitions for words as much as it does concepts from phraseology.
Whereas a Greek noun being anarthrous provides broad qualitative considerations and the possibility of adding the article to increase understanding by individual words co-opping other words or a phrase to conceptualize at the word level, English does that by phraseology and subjecting the nouns and their definitions to the phrase.
For instance...
"I love my mother." "I love my wife."
In English, the functional definition of the word love is determined by the entire context of the phrase; so English speakers don't confuse the differing applications of love, even though it's the same word.
But Greek would use different words for love, each with rich differences in meaning, to the point that 'mother' and 'wife' don't provide the meaning for the word 'love'.
"I love ice cream" or "I love football" or "I love the beach" or "I love my pet" all have different meanings for the same word that are determined by another word. In Greek, the anarthrous sense is always present; and the article can be added for emphasis that turns the entire phrase into a noun as a stand-alone concept to be an entity in the mind.
For example... If a table is holding up a vase and candle, while also having an entire array of dishes for dining; its is not "tabling" to be "doing" this "holding up" of all these other things. It's the very qualitative characteristics of the "it-ness" of a table to have this latent functionality and activity. One would never refer to such "tabling" as a verb. That's the anarthrous Greek noun. Qualitative characteristics and functional activity, but never as "doing" like a verb.
Adding the article not only particularizes, but personifies and conceptualizes (and several other functions). So THE sin personifies someone as having an inner sin condition. THE sins personifies the plurality of inner functionalities, whether they come forth into individual manifested actions or not.
A murderer is a murderer in his heart before ever committing the acting and resulting established act/ion of murder. Likewise, it's the inner qualities and (dys-)functionalities of hatred, envy, and whatever else that culminate in any such act as murder.
This "concupiscence" in the heart is considered no differently than actions. Even the Mosaic Law was predicated more upon the heart than the actions, because it was a covenant, not legislative codification. That's what Jesus took issue with amongst the Pharisees. They had abandoned the covenantal nature of the Mosaic Law to make it only a human system of justice for the Theocracy by exhibiting behavior modification rather than keeping the Law from the heart.
Modern English speakers are the ones who separate the inner condition from outer conduct by misrepresenting renderings such as in 1Corinthians 15:3. This isn't referring to a columnar listing of outward acts alone. It's intrinsically referring to an entire conceptualization of the sinner from the inside out, as evidenced by the plurality of resulting actions. So the focus is on the sin condition as the source of it all, not just the outer behavior that can often just be modified or justified. The indication is much more than that which was on the far side of the verb.