The Greek noun endeixis refers to proof, demonstration, or evidence — a clear showing of something that was previously uncertain or disputed. Paul uses it to describe both God's demonstration of righteousness and the believer's proof of salvation.
Endeixis appears three times in Paul's letters, each time at a pivotal theological moment. In Romans 3:25-26, God presented Christ 'as a demonstration (endeixis) of his righteousness' — the cross is not just a transaction but a public proof that God is both just and the justifier. In 2 Corinthians 8:24, Paul asks the Corinthians to give 'proof (endeixis) of your love' through their generosity. In Philippians 1:28, steadfast faith under persecution is an 'endeixis of their destruction and of your salvation.' Theologically, endeixis reminds us that the gospel makes visible and demonstrable what was hidden: God's righteousness, the believer's love, and the ultimate distinction between those who are saved and those who are not.