The idolatrous practices of the people in ancient times arose from their knowledge of correspondences because everything we see on our planet corresponds to something spiritual–not only trees, but also all kinds of animals and birds as well as fish, and so on. The ancients who were devoted to a knowledge of these correspondences made themselves images that corresponded to heavenly realities, and they took pleasure in them because they signified what was happening in heaven and the church. That is why they placed them not only in their temples but in their homes as well–not to be worshiped but to remind them of the heavenly reality signified by these objects. So in Egypt and elsewhere their images looked like calves, oxen, and snakes as well as children, old people, and young women. This is because calves and oxen mean the feelings and drives of the earthly self, snakes the shrewdness of the sensory self, children innocence and caring, old people wisdom, and young women the desire for what is true, and so on.
Because the ancients had placed these images and statues in and around temples, their descendants, after the knowledge of these correspondences had been lost, began to worship the images and statues themselves as sacred, and eventually regarded them as demigods.
Much the same happened in other nations–with the Philistines’ Dagon in Ashdod, for example (see 1 Samuel 5:1-12). The upper part of Dagon looked human and the lower part looked like a fish, an image devised because a human means intelligence, a fish means knowledge, and intelligence and knowledge become one.
This is also why the ancients’ worship was in gardens and groves depending on the species of trees, and on mountains and hills. Gardens and groves meant wisdom and intelligence, and each tree meant some specific aspect of them. Olive trees, for example, meant good actions done out of love; grapevines meant true insights that arise from doing good; cedars meant a rational understanding of what is good and true; mountains meant the highest heaven; and hills meant the heaven below it.
The survival of the knowledge of correspondences until the Coming of the Lord among the greater part of those in the East is demonstrated in the account of the wise men from that region who came to the Lord when he was born–because in that story a star went before them and they bore gifts of gold, frankincense, and myrrh (Matthew 2:1-2, 9-11). That is, the star that went before them meant a new insight from heaven; and gold meant what is good on the heavenly level, frankincense what is good on the spiritual level, and myrrh what is good on the earthly level; and these are the basis of all worship.
There was no knowledge at all of correspondences among the people of Israel and Judah, however, even though correspondences was the sole basis of all their worship, all the judgments and statues given them through Moses, and all the contents of the Word. This was because they were idolatrous at heart, so much so that they did not even want to know that any element of their worship had a heavenly or spiritual meaning. That is, they wanted all these things to be holy in and of themselves and just for them, so if they had noticed anything heavenly and spiritual, they not only would have rejected it but would have profaned it as well. For this reason heaven was closed to them, so closed that they were scarcely aware that there was such a thing as eternal life. The truth of this is obvious from the fact that they did not recognize the Lord even though the whole Sacred Scripture prophesied about him and predicted him. The sole reason they rejected him was that he taught people about a heavenly kingdom and not an earthly one. That is, they wanted a Messiah who would raise them to supremacy over all the nations in the whole world and not some Messiah who would be concerned with their eternal salvation.
Further, they assert that the Word contains in itself many secrets that they call mystical, but they do not want those secrets to be about the Lord. They do want to know them, though, when they are told that they are about gold.
from Sacre Scripture–White Horse, Section 23