### Core Meaning & Semantic Range
The Greek word **mataióō**, represented by `{{G3154}}`, means to **become vain**. It is used to describe the process of being rendered foolish, morally wicked, or idolatrous. This specific term appears only **1 time** across **1 unique verse** in the Bible, giving it a highly focused and potent meaning within its single context.
### Biblical Occurrences & Contextual Analysis
The sole appearance of `{{G3154}}` is in [[Romans 1:21]], where it anchors a critical argument about the human condition. The verse explains that although people **knew** `{{G1097}}` God, they did not **glorify** `{{G1392}}` Him or show thankfulness. The direct consequence of this ingratitude was that they "**became vain**" in their **imaginations** `{{G1261}}`. This emptiness of thought then led to a further consequence: their **foolish** `{{G801}}` hearts were **darkened** `{{G4654}}`.
### Related Words & Concepts
Several related words from its context clarify the meaning of `{{G3154}}`:
* `{{G1097}}` **ginṓskō** (to "know"): This verb establishes the starting point. The state of becoming vain is a response to a prior awareness of God. This knowledge is not merely academic, as it is the same word used when stating that the Lord **knoweth** His people [[2 Timothy 2:19]].
* `{{G1261}}` **dialogismós** (reasoning, imagination): This is the realm where vanity manifests. It refers to internal considerations or thoughts, which can be corrupted, as when evil **thoughts** proceed from the heart [[Matthew 15:19]].
* `{{G801}}` **asýnetos** (foolish, without understanding): This adjective describes the nature of the heart after it has become vain. It signifies an unintelligent and wicked state, which believers are warned against [[Romans 1:31]].
### Theological Significance
The theological weight of `{{G3154}}` is significant, outlining a clear spiritual progression.
* **The Consequence of Ingratitude:** The primary lesson from [[Romans 1:21]] is that becoming vain is a direct result of failing to glorify or **be thankful** `{{G2168}}` to God. It is not an arbitrary state but a consequence of a specific moral and spiritual failure.
* **Corruption of the Mind:** Vanity is explicitly tied to the "imaginations," or **reasoning** `{{G1261}}`. This indicates that when human thought is detached from its proper object of worship, it becomes futile and morally empty.
* **A Precursor to Darkness:** The state of being vain is an intermediate step toward greater spiritual decay. It leads directly to a **foolish** `{{G801}}` heart that is ultimately **darkened** `{{G4654}}`, showing a causal link between intellectual vanity and spiritual blindness.
### Summary
In summary, `{{G3154}}` **mataióō** is a powerful term that, despite its single use, defines a crucial theological concept. It captures the process by which human intellect and morality become futile and empty as a direct consequence of refusing to honor and thank God. It serves as a stark illustration that true wisdom is rooted in acknowledging God, while turning from Him leads to corrupted reason and a darkened heart.
TRV