The concept of a "church" in the Writings is both complex and beautifully organic, linked with teachings on the nature of the Lord and the resulting nature of mankind.

The Writings say that the Lord, in His essence - His actual substance - is perfect, infinite love, a love that powered creation, that is the ultimate source of reality, and that sustains reality constantly. That love is expressed in form as perfect, infinite wisdom, which gave form to creation and gives form to reality.

Deep stuff! You can read more about that elsewhere, but what matters here is that all of creation, from the smallest elements to the whole of the universe, reflects that same structure. It's present in nature itself, powered by the heat (love) and light (wisdom) of the sun. It's present in the essential forms of life, with plants (which are rooted; which change little; which are unfeeling; which are powered by light) representing elements of wisdom and animals (warm, feeling, mobile, ever-changing, powered by heat) representing forms of love. It's present in the near-universal division into male (wisdom) and female (love) aspects of plants and animals alike.

That structure is also in each of us. In common language we might call these our hearts and our minds - what we want and what we think. The Writings commonly talk of them as good (love; what we want in our hearts) and truth (wisdom; what we know in our minds) or as will (heart) and understanding (mind). Not only do these elements define us, they are also key to our spiritual fates. We can use them to accept the Lord's love, come into the good of life and ultimately go to heaven. We can also use them to reject the Lord's love and trot off to hell.

And there are further layers. The Writings say that all human societies are in human form, with functions analogous to the human body. This is true from small groups like families to large companies to entire nations and ultimately to both the entire human race in this world and the entirety of heaven in the next.

Among the most important human societies are, naturally, churches. Since the concept of a "church" is based on the human form, though, churches as referred to in the Writings can take many forms. At one end of the scale, any one person who has true ideas of right and wrong and lives by them is a church himself or herself. At the other end of the scale, all those in the whole world who believe in love of the neighbor – and act from that belief – collectively make up one church.

Many other varieties lie between those two extremes, but most references to "church" in the Writings mean the community of those who have the Word, know the Lord, and follow His commandments. These people have access to the best possible truth and deepest possible understanding about the nature of the Lord and what He wants from us.

Such a church plays a vital role: The Lord works through it to get ideas about being good into people's minds and the desire to be good into the inner recesses of their hearts, reaching far beyond that church itself to touch everyone in the world. In fact, the Writings say there is in essence a marriage between the Lord and the church, with the church in the role of the bride and wife, producing true ideas and good desires the way a wife produces children.

To protect this function, the Lord has made sure that throughout history (and a good bit of prehistory) there has always been a church filling this role.

The first of these was the Most Ancient Church, represented by Adam; it was inspired by love of the Lord. The second was the Ancient Church, represented by Noah; it was inspired by love of the neighbor and knowledge of the Lord. The third was the Israelitish Church, which had no interior love of good but preserved ideas of the Lord. The fourth was the primitive Christian church, which had a new, more direct understanding based on the Lord's teachings. The fifth, according to the Writings, is to be based on the deeper understanding offered through the Writings and their explanations of the Bible.

There is much more that could be said, but we'll just emphasize one other point:

We as individuals are who we are based on what we love, not what we know. We will go to heaven or to hell based on what we love, not what we know. Knowing, thinking and seeking truth are important things, but their purpose is to shape, guide and serve our loves; love is ultimately what matters. The Writings make it abundantly and repeatedly clear that it is the same with churches: They are ultimately based on love, not knowledge, on their determination to serve the neighbor, not their external forms of worship. And if churches share that common purpose of serving the neighbor then they are in essence one, with doctrinal variations being of little consequence.

(Referencat: Apocalypse Revealed 533; Arcana Coelestia 407, 768, 1799 [3-4], 2048, 2853 [2-3], 2910, 2982, 3310, 3773, 3963 [2], 4292, 4672, 4723, 5826 [2-3], 6637, 6648, 8152, 9256 [4-5], 9276 [2]; Conjugial Love 116; Heaven and Hell 57; The Word 8; The Doctrine of the New Jerusalem Regarding the Sacred Scripture 99, 104)

3310. 'A man of the field' means the good of life that has its origin in matters of doctrine. This is clear from the meaning of 'the field'. In the Word reference is made in many places to the earth (or the land), the ground, and the field. When used in a good sense 'the earth' means the Lord's kingdom in heaven and on earth, and so the Church, which is the Lord's kingdom on earth. 'The ground' is used in a similar though more limited sense, 566, 662, 1066-1068, 1262, 1413, 1733, 1850, 2117, 2118 (end), 2928; and the same things are also meant by 'the field', though in a more limited sense still, 368, 2971. And since the Church is not the Church by virtue of matters of doctrine except insofar as these have the good of life as the end in view, or what amounts to the same, unless matters of doctrine are joined to the good of life, 'the field' therefore means primarily the good of life. But in order that such good may be that of the Church, matters of doctrine from the Word which have been implanted within that good must be present. In the absence of matters of doctrine the good of life does indeed exist, but it is not as yet that of the Church, and so not as yet truly spiritual, except in the sense that it has the potentiality to become so, like the good of life as this exists with gentiles who do not possess the Word and therefore do not know the Lord.

[2] That 'the field' is the good of life in which the things of faith, that is, spiritual truths existing with the Church, are implanted, becomes quite clear from the Lord's parable about the sower in Matthew,

A sower went out to sow, And as he sowed some fell on the pathway, and the birds came and devoured them. Some fell on rocky ground where they did not have much soil, ¹ and immediately they sprang up, since they had no depth of soil ² , but when the sun rose they were scorched; and since they had no root they withered away. Some fell among thorns, and the thorns came up and choked them. But some fell on good soil ² and yielded fruit, some a hundredfold, some sixty, some thirty. He who has an ear to hear let him hear. Matthew 13:4-9; Mark 4:3-9; Luke 8:5-8.

This describes four types of land or ground within the field, that is, within the Church. The fact that here 'the seed' is the Lord's Word, and so the truth which is called the truth of faith, and that 'the good soil' is the good which is called the good of charity is evident to anyone, for it is the good in man that receives the Word. 'The pathway' is falsity, 'rocky ground' is truth which is not rooted in good, 'thorns' are evils.

[3] With regard to the good of life which has its origin in matters of doctrine being meant by 'a man of the field', the position is that those who are being regenerated first of all do good as matters of doctrine direct them, for they do not of themselves know what good is. They learn to do good from matters of doctrine concerning love and charity; from these they know who the Lord is, who the neighbour is, what love is, and what charity is, and so what good is. Those who have come into this stage are stirred by the affection for truth and are called 'men (vir) of the field'. But after that, once they have been regenerated they do good not from matters of doctrine but from love and charity, for the good itself which they have learned about through matters of doctrine exists with them, and they are in that case called 'men (homo) of the field'. It is like someone who is by nature inclined to commit adultery, steal, and murder but who learns from the Ten Commandments that such practices belong to hell and so refrains from them. In this state he is influenced by the Commandments, for he fears hell and learns from those Commandments and similarly from much else in the Word how he ought to conduct his life. In his case when he does what is good he does it from the Commandments. But when good exists with him he starts to loathe adultery, theft, and murder to which he was previously inclined. In this state he no longer does what is good from the Commandments but from the good which by now resides with him. In the first state the truth he learns directs him to good, but in the second state good is the source of truth taught by him.

[4] The same also applies to spiritual truths which are called doctrinal and are more interior Commandments still. For matters of doctrine are interior truths which the natural man possesses, the first truths there being sensory ones, the second truths being factual, and interior truths matters of doctrine. The latter are based on factual truths inasmuch as a person can have and retain no idea, notion, or concept of them except from factual truths. But the foundations on which factual truths are based are sensory truths, for without sensory truths nobody is able to possess factual ones. Such truths, that is to say, factual and sensory, are meant by 'a man skilled in hunting', but matters of doctrine are meant by 'a man of the field'. Such is the order in which those kinds of truths stand in relation to one another in man. Until a person has become adult therefore, and through sensory and factual truths possesses matters of doctrine, he is incapable of being regenerated, for he cannot be confirmed in the truths contained in matters of doctrine except through ideas based on factual and sensory truths - for nothing is ever present in a person's thought, not even the deepest arcanum of faith there, which does not involve some natural or sensory idea, though generally a person is not aware of the essential nature of such ideas. But in the next life the nature of them is revealed before his understanding, if he so desires, and also a visual representation before his sight, if he wants it; for in the next life such things can be presented before one's eyes in a visual form. This seems unbelievable but it is nevertheless what happens there.

Fusnotat:

1285. That 'the whole earth was one lip' means that people everywhere held to the same doctrine in its general aspects is clear from the meaning in the Word of 'a lip', dealt with in the next paragraph. This verse, in these few words, describes the state of the Ancient Church as it had been, that is to say, it held to the same general doctrine. The next verse however describes how it began to be falsified and adulterated, and after that down to verse 9 how it became so utterly perverted that no internal worship existed any longer. Immediately after that the subject is the second Ancient Church begun by Eber, and at last the third Church which was the start of the Jewish Church. For after the Flood there were three consecutive Churches.

[2] In regard to what has been said of the first Ancient Church - that though so wide-spread throughout the world, its lip was nevertheless one and its words one, that is, it shared one doctrine in its general aspects and in its particular details; but for all that, the forms of worship, internal as well as external, were everywhere divergent, as shown in the previous chapter where each nation that is mentioned meant a divergent form of doctrine and of ritual - the situation is as follows: Heaven consists of countless communities. They all vary, and yet all are one, for all are led as one by the Lord; see what has appeared already in 457, 551, 684, 685, 690. A parallel exists in man, in that although internally his body has so many parts, which, like his other organs and limbs, have so many inner parts, each functioning differently from any other, yet all of them, every single one, are nevertheless controlled as one by one soul. A parallel also exists with the human body, which has different ways of exerting its strength and of moving. Nevertheless all are controlled by one motion of the heart and one of the lungs, and together make one. The reason they are able to function as one in this way is that in heaven there is one single influx which is received by everyone according to his own disposition. This influx is an influx of affections from the Lord, from His mercy and life. And although there is one influx only, everything nevertheless conforms and follows as one. And this comes about through the mutual love shared by those in heaven.

[3] Such was the situation with the first Ancient Church that although there were so many forms of internal and external worship, at the general level as many as there were nations, at the specific level as many as there were families making up nations, and at the particular level as many as there were people in the Church, they all nevertheless had 'one lip' and 'their words were one'; that is, they all shared one doctrine in general and in particular. Doctrine is one when all possess mutual love, or charity. Mutual love or charity causes things, though varied, to be one, for it makes one out of varied things. If all, no matter how many - even ten thousand times ten thousand - are governed by charity or mutual love, they have but one end in view, namely the common good, the Lord's kingdom, and the Lord Himself. Variations in matters of doctrine and in forms of worship are like the variations that exist with the physical senses and with the inner parts of man's body, which, as stated, all contribute to the perfection of the whole. Indeed the Lord flows in and works by way of charity though in different ways according to the disposition of each individual. And in so doing He arranges every single person into a proper order, on earth as in heaven. In this way the Lord's will is done, as He Himself teaches, 'on earth as it is in heaven'.