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)

6637. 'These are the names of the children of Israel' means the essential nature of the Church. This is clear from the meaning of' the name as the essential nature, dealt with in 144, 145, 1754, 1896, 2009, 2628, 2724, 3006, 3421; from the representation of 'the sons of Israel' as spiritual truths, dealt with in 5414, 5879, 5951; and from the representation of 'Israel' as the good of truth, which is spiritual good, dealt with in 3654, 4598, 5803, 5806, 5812, 5817, 5819, 5826, 5833. Since Israel' represents the good of truth or spiritual good and 'his sons' represent spiritual truths in the natural, 'the sons of Israel' also represent the Church, for what makes it the Church is spiritual good and the truths that spring from that good. A person without spiritual good, that is, the good of charity, and without spiritual truths, that is, the truths of faith, does not belong to the Church in spite of having been born within the Church. The whole of the Lord's heavenly kingdom possesses the good of love and faith, and unless the Church possesses good like that it cannot be the Church since it is not joined to heaven; for the Church is the Lord's kingdom on earth.

[2] The term 'Church' is not used because it is the place where the Word is and teachings drawn from it, or because it is where the Lord is known and the sacraments are celebrated. Rather it is the Church because it lives in accordance with the Word or with teachings drawn from the Word, and seeks to make those teachings its rule of life. People who do not live like this do not belong to the Church but are outside it; and those who lead wicked lives, thus lives contrary to that teaching, are further away outside the Church than gentiles who know nothing whatever about the Word, the Lord, or the sacraments. For since those people are acquainted with the forms of good that the Church fosters and with the truths it teaches they annihilate the Church within themselves, something gentiles cannot do because they are unacquainted with those things. It should also be realized that everyone who leads a good life, in charity and faith, is a Church, and is a kingdom of the Lord. He is for that reason also called a temple, and a house of God too. Those who are Churches individually, no matter how remote from one another they may be, constitute one Church collectively. This then is the Church meant by the expression 'the children of Israel' here and in what follows.

2910. 'And Abraham came to mourn for Sarah and to weep for her' means a state in which the Lord grieved, that is to say, because it was night as regards the truths of faith within the Church. This is clear from the representation of 'Abraham' as the Lord, dealt with in 1893, 1965, 1989, 2011, 2172, 2501, 2833, 2836. That 'mourning' and 'weeping' mean a state involving grief is clear without explanation. 'Mourning' has regard to grief on account of its being night as regards goods within the Church, and 'weeping' as regards truths. These two verses have dealt with the end of the Church, which arrives when charity does not exist any longer. The end of the Church is the subject many times in the Word, especially in the Prophets and in John, in the Book of Revelation. The Lord too in the Gospels describes that end extensively, calling it the close of the age, and also night.

[2] The situation with all Churches is that initially every Church regards charity as being fundamental. At that time every individual person loves every other as his brother and is moved by good - not on his own account but on account of that person, of the general good of all, of the Lord's kingdom, and above all of the Lord Himself. But with the passage of time charity starts to grow cold and to cease to exist. After that, hatred of one person against another enters in, which - though not apparent outwardly because people in organized society are subject to laws and to external restraints which keep them in check - is nevertheless being fostered inwardly. The external restraints keeping them in check stem from self-love and love of the world, being the love of position and importance, the love of wealth and also of the power that wealth brings, and so the love of reputation. Beneath these loves there lurks hatred of the neighbour, such as leads people to desire dominion over all and to possess everything that belongs to anyone else. And when these desires are opposed, such persons harbour in their mind contempt for that neighbour, breathe revenge, and take delight in his ruin, and indeed perform acts of cruelty on him insofar as they dare. It is into ways such as these that the charity of the Church ultimately goes when it reaches its end. At that time it is said of the Church that faith does not exist any longer, for when there is no charity there is no faith, as has been shown many times.

[3] There have been many Churches, which are known of from the Word, that have come to an end in this fashion. The Most Ancient Church breathed its last in such circumstances around the time of the Flood. So in a similar way did the Ancient Church which existed after the Flood, as also did the second Ancient Church called the Hebrew Church; and later on the Jewish Church. This never was a Church that had charity at the outset, but was merely the representative of a Church whose role was to preserve by means of representatives a communication with heaven until the Lord came into the world. After that a new Church was established by the Lord, which was called the gentile Church and was an internal Church since interior truths from the Lord had then been revealed. But even this Church has now reached its end, for now not only is charity non-existent but also hatred is present instead of charity. Although that hatred is not apparent outwardly it is nevertheless there inwardly and breaks out when at all possible, that is, as often as external restraints do not keep people in check.

[4] In addition to these Churches there have been many others which have not been described so specifically [in the Word] but which deteriorated in a similar way and destroyed themselves. There are many reasons why they have so deteriorated and destroyed themselves. One reason is that parents pile up evils, and from practicing these frequently until at length they become habitual, introduce them into their own nature and disposition, and in so doing hand them down by heredity to their offspring. For what parents acquire through frequent practice in their actual living takes root within their natural disposition and is transmitted by heredity to their descendants. And unless these are reformed or regenerated, that which is transmitted is perpetuated in succeeding generations, increasing all the time as it is passed down. Consequently the will becomes even more bent on evils and falsities. But when the Church reaches its close and perishes the Lord always raises up a new Church somewhere else. Yet rarely, if ever, has He done so from members of the previous Church, but from gentiles who dwelt in ignorance. Those gentiles are the subject in what follows next.