ἴσος

equal, identical

Definition

The adjective ἴσος fundamentally means 'equal' or 'identical,' describing a state of sameness in quantity, quality, or status. In the New Testament, it often denotes equality in a moral or relational sense, such as the 'equal' grace given to Jews and Gentiles (Acts 11:17) or the expectation of receiving 'equal' treatment (Luke 6:34). In a profound theological application, it describes Christ Jesus being 'equal with God' (John 5:18; Philippians 2:6), indicating a shared divine nature and status. It can also refer to literal, measurable equality, as in the dimensions of the New Jerusalem being 'equal' in length, width, and height (Revelation 21:16).

Biblical Usage

ἴσος is used in various contexts across the Gospels, Acts, an Epistle, and Revelation. In narrative passages, it describes the fairness or unfairness of human situations, like the workers in the vineyard expecting equal pay (Matthew 20:12) or the contradictory, 'equal' false testimonies against Jesus (Mark 14:56, 59). Its most significant uses are theological: asserting Jesus's equality with God in John 5:18 and describing his pre-incarnate state in Philippians 2:6. It concludes the canon with a symbolic architectural use in Revelation 21:16.

Etymology

Derived from the Proto-Indo-European root *wi- meaning 'apart, in half,' the Greek ἴσος carries the core idea of balance and evenness. It is related to the Greek verb ἰσόω (isoō, G2470 related) meaning 'to make equal.' This root gives us modern scientific terms like 'isometric' (equal measure) and 'isotope' (same place). Its fundamental sense of equivalence and balance remained stable from classical through Koine Greek.

Semantic Range

This word is central to understanding the divinity of Christ. In John 5:18, the Jewish leaders correctly understand Jesus's actions as 'making himself equal with God' (ἴσον τῷ θεῷ). Paul's use in Philippians 2:6 is even more direct, stating Christ existed in the 'form of God' and did not consider his equality with God (τὸ εἶναι ἴσα θεῷ) something to be exploited. This establishes a core doctrine of the Trinity and Christ's co-equality with the Father, enriching our reading by highlighting the precise language used to confess Jesus's divine nature.

In the Greco-Roman world, the concept of equality (ἰσότης) was a political and social ideal, but it was typically limited to citizens of the same class. The New Testament's application of ἴσος often subverts this, declaring equality in grace between Jews and non-Jews (Acts 11:17) and, most radically, applying it to the relationship between a human and the divine in Christ. This challenged both Jewish monotheism and Greco-Roman social hierarchies.

ὁμοίος (homoios, G3664) — emphasizes similarity or likeness in kind or manner, not necessarily mathematical equality. ἴσος implies a stronger, more precise equivalence.

Word Details

Scripture References