Jeremiah's Letter, also known as the Letter of Jeremiah or Baruch 6, is a deuterocanonical book of the Old Testament, included in the Septuagint and Vulgate versions of the Bible. It's presented as a letter written by the prophet Jeremiah to the Jewish exiles in Babylon. The letter aims to dissuade them from worshipping the idols and false gods prevalent in Babylonian culture.

The verse in question, Jeremiah 6:23, reads: "Whereby you may know that they are no gods: therefore fear them not."

Let's break it down:

"Whereby you may know that they are no gods": This refers to the various ways the letter explains the idols' powerlessness and lack of divinity. The letter highlights the idols' inanimate nature: they are made of wood, silver, and gold; they are carried around; they cannot move themselves; they are vulnerable to thieves; they are adorned and cared for like children because they are helpless. These characteristics demonstrate that they are not true gods, capable of power or agency.

"Therefore fear them not": Since these idols are demonstrably not gods, there is no reason for the Jewish exiles to be afraid of them. True gods are worthy of reverence and fear, but these powerless objects inspire only false fear, stemming from superstition and cultural pressure. The letter encourages the exiles to remain faithful to the one true God of Israel and not be swayed by the practices of the surrounding Babylonian culture.

In essence, the verse is a direct exhortation to the Jewish exiles to recognize the idols for what they are - powerless objects - and therefore to resist the temptation to worship or fear them. The letter empowers them to stand firm in their faith, even amidst a foreign and idolatrous culture. It's a call to critical thinking and spiritual discernment. They should use their reason and faith to see the truth: that these idols have no real power.