The first altar mentioned in the Word was the one built by Noah after he came out of the ark, after being saved from the great flood. On that altar, he sacrificed clean animals to the Lord.

Mountains represent the Lord because of their height; we need to raise our thoughts above worldly things when "talking" with the Lord. An altar is a small artificial mountain. When it's used in worship, it can call to mind this raising of thought. The fire and smoke that rise from an altar are symbolically being sent to the Lord.

Most altars were made from unhewn stones. Stones represent truths. Unhewn stones - ones that have not been shaped by men - represent truths from the Word, truths that have not been adulterated.

The clean beasts to be sacrificed represent good things, charitable acts done because they are right. The clean birds represent thoughts about doctrine and actions, and about what is right. Presenting these things is an acknowledgment that we have them from the Lord, and a giving thanks to Him for them.

In the Israelitish Tabernacle, the altar of burnt offering represented the acknowledgment of good and the altar of incense that of truth. For this reason this larger altar, which was outside by the door, was made of brass which signifies natural good, while the altar of incense was made of gold, which signifies love to the Lord from whom comes truth.

5. And He sent and signified it by His angel to His servant John. This symbolizes the things that have been revealed by the Lord through heaven to people who possess goodness of life arising from charity and its accompanying faith.

"He sent and signified it by His angel" means, in the spiritual sense, things that have been revealed by the Lord from heaven or through heaven. For in the Word an angel frequently means the angelic heaven, and in the highest sense the Lord Himself. That is because no angel ever speaks with a person in dissociation from heaven, for each has such a conjunction with all the rest there that everyone speaks in accord with the communion, even though the angel is not conscious of it.

In the Lord's sight, in fact, heaven is as a single person, whose soul is the Lord Himself. Therefore the Lord speaks with a person through heaven, as a person does from his soul through his body in speaking with another. And this the person does in conjunction with each and every part of his mind, at whose center are the things that he is saying. But this secret cannot be explained in a few words. We have explained it in part in Angelic Wisdom Regarding Divine Love and Wisdom.

In the highest sense the Lord is meant by an angel because heaven is not heaven in consequence of the angels' own qualities, but owing to the Lord's Divinity from which they have their love and wisdom, indeed their life. It is on this account that in the Word the Lord is Himself called an angel.

It is apparent from this that the angel did not of himself speak with John, but that the Lord did so by means of heaven through the angel.

[2] As for saying that this statement means that these things have been revealed to people who possess goodness of life arising from charity and its accompanying faith, that is because it is they who are meant by John. For by the Lord's twelve disciples or apostles are meant all in the church who possess truths arising from goodness, and in an abstract sense, all constituents of the church. By Peter are meant all who are governed by faith, and abstractly, faith itself. By James are meant those who are impelled by charity, and abstractly, charity itself. And by John are meant those who possess goodness of life arising from charity and its accompanying faith, and abstractly, the resulting goodness of life itself. That these are what are meant by John, James and Peter in the Gospels may be seen in the short work The New Jerusalem and its Heavenly Doctrine (London, 1758), no. 122.

[3] Now because goodness of life arising from charity and its accompanying faith is what forms the church, therefore it was through the apostle John that secrets were revealed concerning the state of the church, the secrets that are contained in his visions.

The fact that the names of persons and places in the Word all symbolize things having to do with heaven and the church is something we showed many times in Arcana Coelestia (The Secrets of Heaven), also published in London.

It can be seen from this that the phrase, "He sent and signified it by His angel to His servant John," means, in the spiritual sense, the things that have been revealed by the Lord through heaven to people who possess goodness of life arising from charity and its accompanying faith. For charity produces goodness through faith, and not charity by itself or faith by itself.