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.

9. In the Word there is a spiritual sense which is called its internal sense.

No one can know what is the spiritual or internal sense of the Word unless he knows what correspondence is: 2895, 4322. Every single thing which is in the natural world, right down to the very least thing, corresponds to something spiritual, and so signifies it: 1886-1889, 2987-3003, 3213-3227. Spiritual things, to which the natural things correspond, appear in nature under another guise, with the result that they are not recognized: 1887, 2395, 8920. Hardly anyone knows where divine quality is in the Word, though it is there in its internal or spiritual sense, the existence of which is not known today: 2899, 4989.

What lies hidden in the Word is nothing other than what its internal or spiritual sense contains, in which the Lord, the glorification of His human form, His kingdom, and His Church are dealt with, and not natural things, which are of the world: 4923. In very many places the prophetical elements are not understood, and so are of no benefit, without the internal sensefrom examples in 2608, 8020, 8398 just as what is signified by the White Horse in the Book of Revelation, from 2760. What is meant by the Keys of the Kingdom of Heaven given to Peter: Preface to Genesis 22 and 9410. What is meant by flesh, blood, bread, and wine in the Holy Supper: 8682. What is meant by the prophecies of Jacob concerning his sons: Genesis 49 and 6306, 6333-6465. What is meant by many other prophecies about Judah and Israel which do not match with [aspects of] that nation, and do not coincide with one another in their literal sense: 6333, 6361, 6415, 6438, 6444. In addition there are very many others: 2608. Further, what is said about correspondence may be seen in the work Heaven and Hell, 87-115, 303-310.

Concerning the internal or spiritual sense of the Word in general: 1767-1777, 1869-1879. There is an internal sense in every single part of the Word: 1143, 1984, 2135, 2333, 2395, 2495, 2619. These ideas do not appear in the literal sense but still they are in it: 4442.