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.

(References: 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)

57. We can say the same of the church as we have of heaven, since the church is the Lord's heaven on earth. It also has many components, and yet each is called a church and is a church to the extent that the qualities of love and faith rule within it. In it, the Lord forms a single whole out of the varied elements, and therefore makes a single church out of many churches. ¹

Much the same can be said of the individual member of the church as has been said about the church in general, namely that the church is within and not outside, and that anyone is a church in whom the Lord is present in the qualities of love and faith. ²

Much the same can be said of the individual who has the church within as has been said about the angel who has heaven within, that such an individual is a church in least form as the angel is a heaven in least form. Even more, we can say that the individual who has the church within is a heaven just as much as an angel is, for we have been created to enter heaven and become angels. So anyone who has the quality of goodness from the Lord is an angel-person. ³

It is worth noting what we have in common with angels and what we possess that they lack. We have in common with angels the fact that our deeper levels are formed in the image of heaven and that we also become images of heaven to the extent that we participate in the qualities of love and faith. What we have that angels lack is that our more outward levels are formed in the image of this world; and that to the extent that we are engaged in what is good, the world within us is subordinated to heaven and serves it; ⁴ and that then the Lord is present with us on both levels as he is in his heaven. He is actually present on both levels in his divine order, for God is order. ⁵

Footnotes:

9632. 'And a covering from the skins of badgers above that' means outside that [another mantle], a mantle consisting of truths derived from external good. This is clear from the meaning of 'a covering' as a mantle, as just above in 9630; from the meaning of 'skins' as external truths, dealt with in 9471; and from the meaning of 'badgers' as forms of good, also dealt with in 9471.

Any further explanation of the things which have been stated so far regarding the dwelling-place, the tent over it, and the two coverings over that, can be dispensed with, since they are such as would be scarcely intelligible owing to the lack of proper knowledge. For where that knowledge is lacking there is blindness; thus there is no reception of light nor consequently any concept of the matter. Few if any people know that heaven is represented and thereby described by the dwelling-place, and the external part of it by the tent and its two coverings. The reason why there is no proper knowledge of these things is that scarcely anyone is aware of the fact that heavenly realities are meant by all that is written in the Word, thus that there is an inner meaning or spiritual sense within every detail there. Scarcely anyone knows either that this sense is not apparent in the letter, only from the letter to those who, having learned about correspondences, receive light from the Lord when they read the Word.

[2] Indeed scarcely anyone is aware of the fact that a person governed by the good of love and faith is heaven in the smallest form this can take, or that such a person in respect both of the more internal aspects of his being and of the more external corresponds to heaven, 9276. If these things had been known the learned in the Christian world who have acquired some knowledge regarding the parts of the human body could have received some light of understanding and therefore have had some concept of heaven. They could have discerned which particular realities in heaven are represented by the ark, its mercy-seat, and the cherubs above it; which particular realities by the table on which the loaves of the Presence were laid, the lampstand, and the gold altar for incense; also which particular ones are represented by the dwelling-place, its curtains, boards, and bases, and lastly by the tent and the two coverings over it. For similar things are met with in the human being, in the things with him that are internal and those that are external. They also present themselves in material form in his body; and to these [material parts of his body] the internal things have an exact correspondence. For unless the external things, which belong to the body, had an exact correspondence with the internal ones, which belong to the understanding and the will, there would not be any life in the body, nor thus any actions in accord with them.

[3] Similar things are said to be met with in the tabernacle as in the human being because representatives on the natural level resemble the human form and have the same meaning as the parts of it they resemble, 9496. External things within the human being provide four coverings which surround and enclose all that is more internal; these coverings are what animal skins and actual skins of the body refer to. See what has been mentioned from experience in 5552-5559, 8980, regarding the correspondence of the latter to internal things. The coverings which constituted the roof and sides of the tabernacle provided a similar representation. From all this the understanding may gain some light regarding the forms that heaven takes. Nevertheless that light will be snuffed out with all who have no definite knowledge regarding the things that exist within the human body and at the same time no definite knowledge regarding the spiritual realities belonging to faith and the celestial realities belonging to love, to which those things in the body correspond. Since most people are in the dark, indeed in thick darkness, so far as those realities and human physiology are concerned, owing not only to their lack of knowledge but also to their lack of belief, any further explanation of them has been dispensed with; for as stated above, they would be unintelligible because there is no light of understanding in such matters.