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.

1076. That 'Ham' means the corrupted Church is clear from what has been stated already about 'Ham'. A Church is called corrupted which acknowledges the Word and has a certain worship similar to that of the true Church but nevertheless separates faith from charity, and so separates it from its essential element and very life. As a consequence faith becomes a thing that is dead, with the result that the Church is inevitably corrupted. What kind of people its members become is made clear by the fact that they cannot possibly have any conscience; for conscience that is truly conscience never exists unless it derives from charity. Charity is what makes conscience, that is, the Lord does so by means of charity. What is conscience but not doing wrong to anyone in any way at all, or doing well to everybody in every possible way? So conscience is an attribute of charity and never of faith separated from charity. If such persons do have any conscience it is a false conscience, about which see what has appeared already. And because they are devoid of conscience they rush into everything unspeakable, so far as external restraints are removed.

[2] Nor indeed do these people know what charity is, but only that it is a word having some meaning. And being devoid of charity they do not know what faith is. When questioned they can only reply that it is a sort of thought Some reply that it is trust, others that it is cognitions of faith. A few say that it is living according to those cognitions, while scarcely any say that it is the life of charity, that is, of mutual love. And if they are told this and are given the opportunity to reflect, their only reply is that all love begins from self, and that anyone who does not consider his own interests and his family's is worse than a heathen. Consequently they are concerned about nothing but themselves and the world. This leads to their living in the proprium, the nature of which has been described frequently already. These are the people who are called 'Ham'.