In chapter 4 of the Book of Amos, verses 1-3 are talking about people who pervert the truths of the church. They will fall into falsities in outermost things.

In the Bible, fish represent "lower" things than mammals, so we can interpret the fishhooks in verse 2 as meaning being caught and held fast in natural or lower things.

Verses 4-6 are about acts of worship such as tithes and sacrifices. These look similar to genuine worship, but are only external sorts of things. We can tell because ‘teeth’ (in verse 6) represent ultimates or outermost things (see Secrets of Heaven 6380). It follows that “cleanness of teeth” would mean outermost things that look good but only imitate genuine worship. The Lord exhorts, “Yet you have not returned to me.”

Verses 7-8. Some things true will remain, when where there are too many false ideas, the truths don't get through. This can be seen where the Lord says, “I made it rain on one city; I withheld rain from another city... where it did not rain the part withered.” Again the Lord exhorts, “Yet you have not returned to me.”

Verse 9. Afterward all things of the church are falsified, shown by blight attacking the gardens, vineyards, fig tree and olive trees. The last three represent spiritual, natural and celestial things, or all the things of spiritual life. “Yet you have not returned to me,” says the Lord.

Verses 10-11. The Lord explains the devastating things he allowed to happen: plague in Egypt, death of young men by swords, stench in the camps, Sodom and Gomorrah. This is because they are profaned by sensual knowledges. Profanation means the mixing of good and evil together. (See Secrets of Heaven 1001[2]).

This extends to all things of the church, with the church being the Lord’s kingdom on earth (Secrets of Heaven 768[3]).

With profanation “as soon as any idea of what is holy arises, the idea of what is profane joins immediately to it,” (Secrets of Heaven 301).

Now there is hardly anything left. “Yet you have not returned to Me,” says the Lord again.

Verses 12-13: Because people adamantly remain in their profane ways, they are warned, “Prepare to meet your God!”. This is the God powerful and mighty, “who forms mountains, and creates the wind,” and even more close to home, “Who declares to man what his thought is.” As intimately a knowing as that is, the Lord’s love for all humanity is contained in His exhortations for them to turn themselves to Him.

See, for example, Luke 6:44-45, and True Christian Religion 373.

468. A tree means man, as is proved by the following passages in the Word:

All the trees of the countryside shall know that I, Jehovah, will lay low the tall tree, and raise up the low tree; and I will wither the green tree and make the dry tree sprout, Ezekiel 17:24.

Blessed is he whose pleasure is in the law; he shall be like a tree planted near streams of water, which shall give fruit at its proper time, Psalms 1:2-3; Jeremiah 17:8.

Praise Jehovah, fruit-trees, Psalms 148:9.

Jehovah's trees are fully watered. Ps. 'Psalm 104:16.

The axe lies at the root of the tree; every tree which does not produce good fruit will be cut out, Matthew 3:10; 7:16-21.

Either make the tree good and its fruit good, or make the tree rotten [and its fruit rotten]; for by its fruit the tree is known, Matthew 12:33; Luke 6:43-44.

I shall light a fire which will consume every green tree and every dry tree, Ezekiel 20:47.

It was because a tree means man, that it was commanded that the fruit of a tree used for food in the land of Canaan should be accounted uncircumcised (Leviticus 19:23-24). Since an olive-tree means a man of the celestial church, it is said of the two witnesses who were prophesying, that they were two olive-trees standing close by the God of the whole earth (Revelation 11:4; similarly Zechariah 4:3, 11-12). Also, in David's Psalms:

I am like a flourishing olive-tree in the house of God. Psalms 52[:8].

Also, in Jeremiah:

A flourishing olive-tree with fair fruit has Jehovah called your name, Jeremiah 11:16-17.

There are many other passages, too numerous to quote here.