### Core Meaning & Semantic Range
The Greek word **sklērýnō**, represented by `{{G4645}}`, means to indurate or, figuratively, to render stubborn. It appears **6 times** across **6 unique verses** in the Bible. This term is used to describe the hardening of one's heart, a state of stubborn resistance or unbelief.
### Biblical Occurrences & Contextual Analysis
In the biblical narrative, `{{G4645}}` is primarily used as a solemn warning. The book of Hebrews repeatedly cautions believers, "**Harden** not your hearts, as in the provocation" ([[Hebrews 3:8]], [[Hebrews 3:15]]). This state is directly linked to the danger of being **hardened** through the "deceitfulness of sin" [[Hebrews 3:13]]. In Acts, the term describes individuals who "were **hardened**, and believed not" [[Acts 19:9]]. The concept is also framed as an act of divine will in Romans, which states that God has mercy on whom He wills, "and whom he will he **hardeneth**" [[Romans 9:18]].
### Related Words & Concepts
Several related words help clarify the context and consequences of being hardened:
* `{{G539}}` **apátē** (delusion): This word for **deceitfulness** is identified as a direct cause of hardening. Believers are exhorted daily lest they be hardened by the "deceitfulness of sin" [[Hebrews 3:13]].
* `{{G544}}` **apeithéō** (to disbelieve): To be hardened is closely associated with willful disbelief. In Ephesus, some were **hardened** and as a result "believed not" [[Acts 19:9]].
* `{{G1653}}` **eleéō** (to compassionate): This term for showing **mercy** is presented as the divine counterpoint to hardening. It establishes a contrast between God's compassion and His sovereign will to harden [[Romans 9:18]].
### Theological Significance
The theological weight of `{{G4645}}` is significant, highlighting critical spiritual principles.
* **A Response to God's Voice:** The command to not **harden** one's heart is consistently presented as the proper response "if ye will hear his voice" ([[Hebrews 3:15]], [[Hebrews 4:7]]), framing it as a crucial human choice.
* **Caused by Sin and Deceit:** The Bible warns that this hardened condition is not random but can be a direct result of sin's influence, specifically its **deceitfulness** [[Hebrews 3:13]].
* **Divine Sovereignty:** The concept also encompasses God's sovereign prerogative. [[Romans 9:18]] clearly states that just as God chooses to have **mercy**, He also chooses whom He **hardeneth**, placing the ultimate action within His will.
### Summary
In summary, `{{G4645}}` signifies more than simple stubbornness; it is a critical spiritual state. It describes a heart rendered unresponsive, whether through the influence of sin and disbelief or as an act of God's sovereign judgment. The repeated warnings against it underscore the importance of maintaining a soft heart that is able to hear and respond to God's voice.
TRV