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)

4292. In the internal historical sense 'he said, Your name will no longer be called Jacob, but Israel' means that they could not as [the descendants of] Jacob play the representative part, except by virtue of the new nature that was imparted to them. This becomes clear from the meaning of 'Jacob' in the Word as his descendants, dealt with above in 4281, and from the meaning of 'name' as the essential nature, dealt with immediately above in 4291. The new nature itself is meant by 'Israel' in the internal sense, for 'Israel' is the celestial-spiritual man and consequently the internal man, 4286. And since 'Israel' means the celestial-spiritual man, and so the internal man, 'Israel' also means the internal spiritual Church. For whether you use the expression spiritual man or spiritual Church, it amounts to the same thing because any spiritual person in particular is the Church, even as many are in general. If the individual person in particular were not the Church, no Church in general could exist. The expression Church is used in everyday language to describe a congregation in general; but each member of the congregation must be a Church if that greater Church is to exist. Every general whole incorporates parts that are like that whole.

[2] The implications of this particular matter - the inability of [the descendants on Jacob to play the representative part, except by virtue of the new nature imparted to them, meant by 'Israel' - are as follows: It was specifically Jacob's descendants who were to represent the Church but not specifically Isaac's since Isaac's descended not only through Jacob but also through Esau. Still less was it specifically Abraham's, for Abraham's descended not only through Jacob but also through Esau, and likewise through Ishmael, as well as through his sons by his second wife Keturah, who were Zimran, Jokshan, Medan, Midian, Ishbak, Shuah, and the sons of these, see Genesis 25:1-4. Now because Jacob's descendants insisted that they should be representative, as shown just above in 4290, they could not represent as Jacob, or as Isaac, or as Abraham. The reason why they could not do so as Jacob was that 'Jacob' represented the external aspect of the Church, but not the internal. And they could not do so as Isaac at the same time or as Abraham at the same time for the reason advanced immediately above.

[3] So that they could represent the Church therefore, a new name had inevitably to be given to Jacob, and through that name a new nature, which new nature was to be a sign of the internal spiritual man, or what amounts to the same, of the internal spiritual Church. That new nature is meant by 'Israel'. Every Church of the Lord is internal and external, as has been shown several times already, the internal Church being that which is represented, the external that which represents. The internal Church is also either spiritual or else celestial, the internal spiritual Church being represented by 'Israel', but the internal celestial Church at a later time by 'Judah'. Therefore a division also took place, and the Israelites became a kingdom on their own and the Jews another on their own. But these matters will in the Lord's Divine mercy be discussed later on. From this it is evident that 'Jacob', that is, Jacob's descendants, could not represent the Church as Jacob, for that would have been to represent solely the external aspect of the Church. They had to do so as Israel as well because 'Israel' is the internal aspect.

[4] It has been shown in various places already that it is the internal which is represented and the external which represents, as may also be seen in the human being. A person's speech represents his thought, and a person's action represents his will. Speech and action are the external aspects of the person, thought and will the internal. In addition the various looks seen on a person's face represent both, that is to say, both his thought and his will. It is well known to everyone that the looks on a person's face are representative, for the looks on the faces of people who are sincere enable their interior states to be seen. In short, every part of the body represents some facet of a person's inclination (animus) and mind (mens).

[5] It is similar with the external aspects of the Church, for these are like the body, while its internal aspects are like the soul. There were, for example, the altars and the sacrifices on them, which, as is well known, were external things. There was likewise the bread of the presence, also the lampstand with its lamps, as well as the fire that was kept burning all the time. Anyone can recognize that these external things represented internal ones, as likewise did everything else of a ritual nature. The fact that these external things could not represent anything external, only what was internal, becomes clear from the considerations introduced already. So 'Jacob' could not represent as Jacob, because 'Jacob' means the external aspect of the Church, but he could do so as Israel because 'Israel' means its internal aspect. This is what is meant by a new nature being imparted to enable the descendants of Jacob to play the representative part.

5803. 'We have a father, an old man' means that spiritual good is their source. This is clear from the representation of Israel, to whom 'a father refers here, as spiritual good, which is the source, dealt with just above in 5801. As regards Israel's representation, see 4286, 4292, 4570, where it is shown that he represents the spiritual Church, in particular the internal aspect of it, which is the good of truth or spiritual good from the natural. What spiritual good or the good of truth is, see 5526, 5773.