Hebrew uses the grammatical singular for countables, for collectives, and for class nouns. . . . With countables the singular serves to enumerate one object.
"The earth" in Genesis 1:2 is an early example. He continues (pp. 113-114):
With collectives the singular designates a group. Some words in Hebrew, like 'fish,' 'sheep,' and 'fruit' in English, are treated as collectives and represented by the singular. . . . Like English, Hebrew may use the article with a singular noun to indicate a particular class or group; cf. 'The lion is king of the beasts.'. . . Hebrew may use the singular with this meaning even without the article, especially in poetry.
"The ungodly" in Psalm 1:1 is an example of a "class noun." It is not referring to any one, particular person, but a class of individuals. As in the use of "the lion," there must be an actual, real lion for there to be the class of such. "The ungodly" means there are many, separate ungodly individuals.
Herbert Weir Smyth in his Greek Grammar for Colleges writes:
The article . . . marks objects as definite and known, whether individuals (the particular article) or classes (the generic article).
The singular noun with "the" is either particular or generic as two general categories. Using Waltke's vocabulary, we have "countable" nouns in the singular and "class" nouns in the singular, unless it is a collective, at which times it can be plural. "The fish" might be more than one, but only in the instance of a collective. Otherwise, the singular is either a countable or a class, a particular or a generic.
Everything that I've written about above is actually well-known and not complicated.
"Generic" should not be confused with a usage that is a type of particular, namely, "anaphoric," in which a singular noun looks back in a sentence (ana = up) for a referent, example: "Susan broke the plate." Sometimes, instead of anaphoric, it is cataphoric, where we look forward in the text to understand to what that singular noun refers specifically (cata = down). Anaphoric and cataphoric are still particular usages, because they mark a particular with the context, either backward or forward, up or down.
Now let's consider it as it applies to the singular "church," when not referring to a particular church. Whether the singular noun is generic is determined by the context. There are 71 usages of "the church" in the New Testament. Between Matthew and the end of Acts, there are no generic usages of "the church" -- that's 17. There are none in Romans, and then after five particular usages in 1 Corinthians, we read one supposed or apparent generic in 1 Corinthians 12:28.
And God hath set some in the church, first apostles, secondarily prophets, thirdly teachers, after that miracles, then gifts of healings, helps, governments, diversities of tongues.
The next 10 usages in 1 Corinthians and Galatians are all particular. Then we get to Ephesians, which contains quite a few of the supposed or generic usage(s). Bear in mind, that it's possible to interpret any usage of "the church" in these epistles as either anaphoric or cataphoric, since the church members would be thinking of their own church in the context. I believe those would be typical anaphoric or cataphoric usages. Christ is the Head of the church -- "sure, our church; Christ is the Head of it." However being as generous as possible, the following could be generic usages:
Ephesians 1:22 -- And hath put all things under his feet, and gave him to be the head over all things to the church,
Ephesians 3:10 -- To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God,
Ephesians 3:21 -- Unto him be glory in the church by Christ Jesus throughout all ages, world without end. Amen.
Ephesians 5:23, 24, 25, 29, 32 -- 23 For the husband is the head of the wife, even as Christ is the head of the church: and he is the saviour of the body. 24 Therefore as the church is subject unto Christ, so let the wives be to their own husbands in every thing. 25 Husbands, love your wives, even as Christ also loved the church, and gave himself for it; 29 For no man ever yet hated his own flesh; but nourisheth and cherisheth it, even as the Lord the church: 32 This is a great mystery: but I speak concerning Christ and the church.
Colossians 1:18, 24 -- 18 And he is the head of the body, the church: who is the beginning, the firstborn from the dead; that in all things he might have the preeminence. 24 Who now rejoice in my sufferings for you, and fill up that which is behind of the afflictions of Christ in my flesh for his body's sake, which is the church:
Besides one usage in Philippians, which is particular, all the usages after Colossians 1:18, 24 are surely particular, 23 uses.
The reason, I think it is safe to say that they are still particular in an "anaphoric" or "cataphoric" sense is that Paul was writing to "the church at Corinth," "the church at Ephesus," and "the church at Colossae." Corinth had there all the offices mentioned in 1 Coirnthians 12:28 at one time or another. When Paul wrote that Jesus was "the head of the church," the church members would think of their own church. If I was talking to my own church, and said "Jesus is the Head of the church," they would be thinking of themselves. That is an actual anaphoric usage. Sure, as we all read it now, we think that "the church" is our own church. That's why I'm saying that I'm being generous, I believe, to designate these as "generic" uses of the singular.
Alright. With all of the above being said, in the Hebrew and Greek, there are abstract nouns that are used in the singular, like knowledge, truth, charity, faith, hope, and joy. "Church" is not an abstract noun. It is concrete. As I also mentioned above, there are collective nouns, used like the singular, such as fish and sheep. "Fish" is the same form for the singular or the plural. "Church" is not one of those. It is not a collective noun. The plural of "church" is "churches." This should be a huge cue to those who say it is a collective, which I have actually read in several places. It would seem that only the gullible would go for that, in light of all the uses of "churches" in the New Testament.
There is no category of spiritual or metaphorical noun. Nouns can be used as a metaphor. For instance, I could say, "Today is a prison and I am the inmate." "The inmate" is used as a metaphor, but it is still a concrete noun. It isn't abstract or a collective. In this case it is used as a particular, because the inmate is a particular person. "Church" is not used as a metaphor in the Bible. "Door" is. "Bread" is. "Church" isn't. There is no metaphorical or spiritual or platonic usage of "church" in the Bible. It is either a generic or a particular. If it is a generic, it is still a church as church is used all its other times.
Recently, I heard someone say something I had never heard or read before. If it is new in your reading -- you had never heard it or read it before and couldn't find it in any writing -- it's probably being made up. What I heard was that there are two meanings of "church," like there are two meanings of other words, like "justify" or "for." How do you know there are different meanings to words? Those are words where it is plain that there is more than one meaning. Most Greek prepositions have multiple meanings, that we can discern by how they are used. "Justify" has nuances of difference in meaning, but "justify" still works in both contexts. Abraham was justified by works -- before men -- not before God. His works declared him righteous to men. You get this kind of nuance of difference in words, but they don't change drastically from their root meanings.
"Church" (ekklesia) means "assembly" and what else? It would be very, very strange for a word that means "assembly" to also mean "not assembly," something contradictory to its root meaning. My default position would be not believing such a dual meaning. I would start with rejection and then wait for very incredible, plain, clear proof. I would expect both countable and class, particular and generic, singulars, but they wouldn't change the meaning.
"The church" is a singular noun with a definite article, so it can be a particular or a generic. It still means "assembly." It can't be universal, because assemblies aren't universal. Assemblies aren't catholic. Assemblies are local only. The church is local only.