Ἐραυνᾶτε in v 39 should be taken as indicative, as δοκεῖτε: “You search the Scriptures because you
suppose you have in them eternal life.” The conviction is expressed frequently
in rabbinic writings. Pirqe ˒Abot 27 reports Hillel as saying, “If a man … has
gained for himself words of the Law, he has gained for himself life in the
world to come.” R. Akiba’s witness is particularly significant; living after
the destruction of the temple, his faith was essentially faith in the
Scriptures. He stated, “God said: the word is not an ‘idle’ thing for you, Deut
32:47; and if it is idle for you, why is it so? Because you do not know how to
search it, for you do not energetically occupy yourself with it. For it is your
life. When is it your life? When you exert yourself with it” (Gen. Rab. 1.19, cited by Schlatter, Der Glaube im NT, 57). V 39 constitutes a denial of this view: “You suppose wrongly that you have life in them.” The
Scriptures were given by God to witness to the Christ, that his people might
come to him and through him gain the life of which they give promise. To search the
Scriptures and reject their testimony to Christ is to frustrate the purpose of
God in giving it to them. (George R. Beasley Murray, John [Word
Biblical Commentary 36; Dallas: Word, Incorporated, 1999], 78-79)
Further Reading:
Not By Scripture Alone: A Latter-day Saint Refutation of Sola Scriptura