proof: the evidence or demonstration by which something hidden is brought into the open and shown to be real
At its heart this word means bringing something hidden out into the open so that its true nature can be seen. In everyday Greek it named the proof or evidence that settles a question: the argument that overturns a false claim, the testimony that convicts in court, the test that shows what a thing really is.
The New Testament uses this particular noun only once, in Hebrews 11:1, where faith is called the proof of things not seen. The point is bold: just as hard evidence makes an unseen fact certain in a courtroom, faith is what makes invisible realities solid and sure to the believer. Older English Bibles translated it "evidence"; newer ones often say "conviction" or "assurance." In the same verse faith is also called the ground that undergirds what we hope for (ὑπόστασις), so the two words work as a pair, one naming faith's grip on the future, the other its grip on the unseen.
A close relative of this word carries a sharper, moral edge. The related verb (ἐλέγχω) usually means to expose, convict, or rebuke, and the New Testament uses it that way of the Spirit convicting the world and of correcting a fellow believer. Hebrews keeps the same basic action, bringing something to light, but aims it at unseen realities rather than at sin.
Disputed
Whether ἔλεγχος in Hebrews 11:1 denotes an objective proof or demonstration of unseen realities or the subjective inner conviction that faith produces in the believer.
- majorityObjective: proof, evidence, or demonstration of things unseen. Grounded in the parallel treatment of ὑπόστασις and in the observation that no Greek text outside Hebrews 11:1 uses ἔλεγχος of a merely psychological state; this is the dominant modern lexical reading.; BDAG, s.v. ἔλεγχος; Harold W. Attridge, The Epistle to the Hebrews (Hermeneia, 1989); Helmut Köster, ὑπόστασις, in Theological Dictionary of the New Testament (TDNT) 8:585-588; Ceslas Spicq, Theological Lexicon of the New Testament, s.v. ἔλεγχος
- minoritySubjective: the inner conviction or assurance that God gives the believer, taken in parallel with a subjective reading of ὑπόστασις as "assurance." This is the older Reformation tradition.; Friedrich Büchsel, ἐλέγχω, ἔλεγχος, ἐλεγμός, in Theological Dictionary of the New Testament (TDNT) 2:473-476; F. F. Bruce, The Epistle to the Hebrews (NICNT, rev. 1990); William L. Lane, Hebrews 9-13 (Word Biblical Commentary 47B, 1991)
- minorityMediating: a reasoned conviction that arises from evidence, holding the objective ground and the inner certainty together.; Paul Ellingworth, The Epistle to the Hebrews (NIGTC, 1993); Peter T. O'Brien, The Letter to the Hebrews (Pillar, 2010)