In general, trees represent the deepest and most significant intellectual concepts: the ones that come to us most directly from the Lord. This varies depending on us and our states: the people of the Most Ancient Church, who were in a state of loving the Lord, understood truth automatically and internally through what the Writings call "perception"; people in lower states (including most of us) have to work a little harder to learn it from the Word and by willing to follow the Lord. In other parts of the Bible, especially in the prophets and New Testament parables, the meaning of "tree" is broader, meaning not just a person's intellectual concepts but the whole person.

'Trees,' as in Joel 1:10-12, signify knowledges.

122. To angels, our world's sun looks like something murky opposite to heaven's sun, and our moon like something dim opposite to heaven's moon, consistently. This is because our world's fire corresponds to a love for ourselves, and the light it emits corresponds to the distortion that arises from that love. Love for oneself is the absolute opposite of divine love, and the distortion that arises from it is the absolute opposite of divine truth. Anything that is opposed to divine love and truth is darkness to angels.

This is why in the Word, worshiping our world's sun and moon and bowing down to them means loving oneself and the distortion that arises from self-love, and why these are to be abolished (Deuteronomy 4:19; 17:3-5; 18:0, Jeremiah 8:1-2, Ezekiel 8:15-16, 18, Revelation 16:8, Matthew 13:6). ¹

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