Now faith is (estin de pisti). He has just said that "we are of faith" ( 1 Thessalonians 10:39 ), not of apostasy. Now he proceeds in a chapter of great eloquence and passion to illustrate his point by a recital of the heroes of faith whose example should spur them to like loyalty now. The assurance of things hoped for (elpizomenwn upostasi). Hupostasis is a very common word from Aristotle on and comes from upisthmi (upo, under, isthmi, intransitive), what stands under anything (a building, a contract, a promise). See the philosophical use of it in 1 Thessalonians 1:3 , the sense of assurance (une assurance certaine, Mngoz) in 1 Thessalonians 3:14 , that steadiness of mind which holds one firm ( 2 Corinthians 9:4 ). It is common in the papyri in business documents as the basis or guarantee of transactions. "And as this is the essential meaning in Hebrews 11:1 we venture to suggest the translation 'Faith is the title-deed of things hoped for'" (Moulton and Milligan, Vocabulary, etc.). The proving of things not seen (pragmatwn elegco ou blepomenwn). The only N.T. example of elegco (except Textus Receptus in 2 Timothy 3:16 for elegmon). Old and common word from elegcw ( Matthew 18:15 ) for "proof" and then for "conviction." Both uses occur in the papyri and either makes sense here, perhaps "conviction" suiting better though not in the older Greek.