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.

28. Everything we have said so far is taught by the Word in many places, of which we will cite only the following.

The Word teaches that no one can be governed by good and at the same time by evil, or in other words, that no one can be with his soul in heaven and at the same time in hell. It teaches this in the following passages:

No one can serve two masters; for either he will hate the one and love the other, or else he will be loyal to the one and despise the other. You cannot serve God and mammon. (Matthew 6:24)

How can you speak good things when you are evil? ...out of the abundance of the heart the mouth speaks. A good man out of the good treasure of his heart brings forth good things, and an evil man out of the evil treasure brings forth evil things. (Matthew 12:34-35)

...a good tree does not bear bad fruit, nor does a bad tree bear good fruit. ...every tree is known by its own fruit. For men do not gather figs from thorns, nor do they gather grapes from a bramble bush. (Luke 6:43-44)