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)

2853. 'In your seed all the nations of the earth will be blessed' means the salvation of all who are endowed with good. This is clear from the meaning of 'being blessed' as being enriched with celestial and spiritual good (dealt with in 981, 1096, 1420, 1422) and - since those who are saved are the subject - as being saved, for as is well known 'being blessed' has a wide range of meanings; from the meaning of 'seed' as faith that is the expression of charity, dealt with in 1025, 1447, 1610; and from the meaning of 'the nations of the earth' as those who are endowed with good, dealt with in 1159, 1258-1260, 1416, 1849.

[2] In addition to this, these words contain the following arcanum: By means of the Church, meant here by 'the earth', 662, 1066, 1068, 1262, those people are saved who are outside of the Church, for 'your seed', as has been stated, means faith that is the expression of charity. Faith that is the expression of charity occurs only with those within the Church since such faith is in essence truth taught by doctrine coupled to goodness of life. For the truth of the matter is that the Lord's kingdom on earth consists of all those who are endowed with good, who, though spread throughout the whole world, are nevertheless one, and as members constitute one body. The same is so with the Lord's kingdom in the heavens. There the whole of heaven presents itself as one entire human being, which is for that reason also called the Grand Man, 684, 1276. And what is a marvel and unknown until now, all parts of the human body correspond to communities in heaven. For this reason it is sometimes said that this group of communities belong to the province of the head, that group to the province of the eye, another group to that of the chest, and so on. This correspondence will in the Lord's Divine mercy be discussed in a section by itself.

[3] It is similar with the Lord's Church on earth. Here the Church is like the heart and lungs, and those outside of the Church resemble parts of the body which are sustained by, and get their life from, the heart and lungs. From this it is evident that without the Church somewhere on earth the human race cannot continue to exist, even as the body cannot without the heart and lungs in it, see 468, 637, 931, 2054. It is for this reason that as often as any Church reaches its end, that is, ceases to be a Church because no charity exists any more, the Lord in His Providence always raises up a new one. When for example the Most Ancient Church, which was called Man, perished, the Lord created a new one, which was referred to as Noah. This was the Ancient Church, which existed after the Flood. And when this declined and became no longer a Church, the Jewish and Israelite representative Church was brought into being. And when this became wholly extinct the Lord came into the world and again established a new one. This was done by Him to the end that heaven might be joined to the human race by means of the Church. This is also what is meant by the words 'in your seed all nations of the earth will be blessed'.

1422. That 'I will bless those who bless you' means pure happiness to those who from their hearts acknowledge the Lord becomes clear from the meaning of 'blessing', which includes every single thing received from the Lord, both that which is good and that which is true, thus every celestial, spiritual, natural, worldly, or bodily form of what is good and true. And because in the universal sense 'blessing' embraces all of these, the meaning of 'to bless' in individual places may be seen from the context in which it occurs, for it fits in with those matters to which it then refers. From this it is clear that 'I will bless those who bless you' means pure happiness to those who from their hearts acknowledge the Lord, since here in the internal sense, as has been stated, the Lord is the subject.

[2] 'Blessing Jehovah (or the Lord)' was an expression used commonly among the ancients, as is clear in the Word, for example in David,

Bless God in the assemblies, even the Lord from the fountain of Israel. Psalms 68:26.

In the same author,

Sing to Jehovah, bless His name, proclaim His salvation from day to day. Psalms 96:2.

In Daniel,

In the vision of the night the arcanum was revealed. Therefore Daniel blessed the God of heaven; he said, Let the name of God Himself be blessed for ever and ever, for wisdom and power are His. Daniel 2:19-20.

And one also reads of Zechariah and Simeon blessing God, Luke 1:64; 2:28. Here it is evident what 'blessing the Lord' implies, namely singing to Him, proclaiming His salvation, declaring His wisdom and power, and so confessing and acknowledging Him from the heart. People who do so are most certainly blessed by the Lord, that is, they are gifted with those things which constitute blessing, namely celestial good, spiritual good, natural good, worldly good, and bodily good, and when these forms of good flow consecutively in this order happiness exists within them.

[3] Since 'blessing Jehovah (or the Lord)' and 'being blessed by Jehovah (or the Lord)' were expressions used commonly among the ancients it was therefore also common to say 'Blessed be Jehovah', as in David,

Blessed be Jehovah, for He has heard the voice of my prayers. Psalms 28:6.

In the same author,

Blessed be Jehovah, for He has made His mercy marvellous to me. Psalms 31:21.

In the same author,

Blessed be God, who has not cast away my prayers, nor His mercy from me. Psalms 66:20.

In the same author,

Blessed be Jehovah God, the God of Israel, who alone does wondrous things; and blessed be the name of His glory for ever; let the whole earth be filled with His glory. Psalms 72:18-19.

In the same author,

Blessed are You, O Jehovah, teach me Your statutes! Psalms 119:12.

In the same author,

Blessed be Jehovah, my rock, who trains my hands. Psalms 144:1.

In Luke,

Zechariah was filled with the Holy Spirit, and prophesied, saying, Blessed be the God of Israel, for He has visited and brought deliverance to His people. Luke 1:67-68.