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.

(Reference: 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)

4723. 'They saw him from a distance' means the Lord's Divine Human perceived remotely. This is clear from the meaning of 'seeing' as perception, dealt with in 2150, 3764; from the meaning of 'from a distance' as remotely; and from the representation of 'Joseph' - the one they saw from a distance - as the Lord as regards Divine Truth, dealt with in 4669. The reason the Lord's Divine Human is what 'Joseph' is used to mean here is that His Divine Human is the highest aspect of Divine Truth. There are two essentials which constitute the Church and as a consequence it has two main teachings, the first being that the Lord's Human is Divine, the second that love to the Lord and charity towards the neighbour constitute the Church, not faith separated from these. Being the primary aspects of Divine Truth, these too are represented by 'Joseph'. Anyone who represents Divine Truth in general also represents the specific aspects of Divine Truth. But which specific aspect is represented at any point is evident from the train of thought.

413. And a third of the sun was struck, a third of the moon, and a third of the stars, and a third of them was darkened. This symbolically means that because of their evils springing from falsities and their falsities springing from evils, they did not know what love is, or what faith is, or any truth.

A third means, symbolically, all (no. 400). The sun symbolizes love (no. 53). The moon symbolizes intelligence and faith (no. 332). The stars symbolize concepts of truth and goodness from the Word (no. 51). To be darkened means, symbolically, to be unseen and unknown because of evils springing from falsities and falsities springing from evils.

Evils springing from falsities are found in people who adopt falsities having to do with religion and defend them to the point that they appear to be true. Then, when they live in accordance with them, they do evils as a result of the falsities, or the evils of falsity.

On the other hand, falsities springing from evils are found in people who do not regard evils as being sins, and still more in people who employ reasonings issuing from their natural self, and moreover from the Word, to establish in themselves that evils are not sins. Their very arguments are falsities springing from evils, and what we call the falsities of evil.

[2] Darkness symbolizes these falsities because light symbolizes truth, and when the light has been extinguished, darkness is left.

To confirm this we will first cite passages where things similar to those here in the book of Revelation are said regarding the sun, moon and stars, and darkness ensuing upon their being extinguished:

The sun shall be turned into darkness, and the moon into blood, before the coming of the great and terrible day of Jehovah. (Joel 2:31)

...the stars of heaven and their constellations will not give their light; the sun will be darkened in its rising, and the moon will not cause its light to shine. (Isaiah 13:10, cf. 24:21, 24:23)

When I extinguish you, I will cover the heavens..., I will cover the sun with a cloud, and the moon shall not give its light. All the luminaries of light in the heavens I will make dark over you, and bring darkness upon your land... (Ezekiel 32:7-8)

...the day of Jehovah... is at hand... The sun and moon grow dark, and the stars diminish their brightness. (Joel 2:1, 10)

Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light, and the stars will fall from heaven... (Matthew 24:29, cf. Mark 13:24-25)

Who, if he elevates his mind, cannot see that in these places it is not the world's sun, moon and stars that are meant.

[3] That darkness symbolizes falsities of various kinds is clear from these passages:

Woe to you who desire the day of Jehovah! ...It will be one of darkness, and not light... Is not the day of Jehovah darkness and not light? Very dark, without any brightness? (Amos 5:18, 20)

(The day of Jehovah will be) a day of darkness and thick darkness, a day of clouds and overcast... (Zephaniah 1:15)

In that day... it will look to the land, which, behold, will be darkness...; and the light will grow dark in its ruins. (Isaiah 5:30, cf. 8:22)

...behold, the darkness covers the earth, and thick darkness the peoples. (Isaiah 60:2)

Give glory to Jehovah... before He causes darkness...; you look for light, but He turns it into thick darkness. (Jeremiah 13:16)

We look for light, but there is darkness and no brightness; we walk in thick darkness... We stumble at noonday as at twilight; among the living we are as dead men. (Isaiah 59:9-10)

Woe to those... who put darkness for light, and light for darkness. (Isaiah 5:20)

The people who walked in darkness have seen a great light. (Isaiah 9:2, cf. Matthew 4:16)

...the rising sun from on high (has appeared) to those who sit in darkness and in the shadow of death... (Luke 1:78-79)

If you give your soul to the hungry..., your light shall rise in the darkness, and your thick darkness shall be as the noonday. (Isaiah 58:10)

In that day... the eyes of the blind who are in thick darkness and gloom shall see. (Isaiah 29:18, cf. 42:16; 49:9)

(Jesus said,) "I am the light of the world; he who follows Me shall not walk in darkness, but shall have the light of life." (John 8:12)

Walk while you have the light, lest darkness overtake you... I have come as a light into the world, that whoever believes in Me should not abide in darkness. (John 12:35, 46)

When I sit in darkness, Jehovah is a light to me. (Micah 7:8)

This is the judgment, that the light has come into the world, but men loved the darkness more than light... (John 3:19, cf. 1:4-5)

If... the light that is in you is darkness, how great is that darkness! (Matthew 6:23, cf. Luke 11:34-36)

...this is your hour, and the power of darkness. (Luke 22:53)

Darkness in these places symbolizes falsity arising either from ignorance of truth or from some false tenet of religion, or from a life of evil.

Regarding people caught up in falsities having to do with religion, who are therefore caught up in evils in life, the Lord says that they should be "cast out into outer darkness" (Matthew 8:12, cf. 22:13; 25:30).