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.

1100. That 'Japheth' means a corresponding external Church has been discussed already; so also has what is meant by an external Church, namely that it is external worship, and so people who do not know what the internal man is and what belongs to the internal man, but who nevertheless lead charitable lives. With them the Lord is just as much present, for the Lord works by means of charity wherever charity exists. It is as with young children. Although these do not know what charity is, still less what faith is, the Lord is nevertheless far more present with them than with adults, especially when young children lead mutually charitable lives. He is in the same way present with simple people who have innocence, charity, and mercy within them. A person's knowing much counts for nothing if he does not live in accordance with what he knows, for the sole purpose of knowledge is that by means of it a person may become good. Once he has become good he possesses far more than someone who knows a vast amount and yet is not good, for what the latter seeks to find through many channels, the former possesses already. It is altogether different in the case of one who knows many truths and goods, and who at the same time has charity and conscience and is a member of the internal Church, which is 'Shem'. People who know little but have conscience are enlightened in the next life even to the point of their becoming angels whose wisdom and intelligence are beyond description. These people are meant by 'Japheth'.