Luther on John 8:25
They desire to know who he is and not what he says. He desires them first to listen and then they will know who he is. The rule is: listen and allow the word to make the beginning, then the knowing will nicely follow. If, however, you do not listen, you will never know anything. For it is decreed, God will not be seen, known, or comprehended except through his word alone. Whatever therefore one undertakes for salvation apart from the word is in vain. God will not respond to that. He will not have it. He will not tolerate any other way. Therefore, let his book in which he speaks to you be commended to you. For he did not cause it to be written to no purpose. He did not want us to let it lie there in neglect, as if he were speaking with mice under the bench or with flies on the pulpit. We are to read it, to think and speak about it, and to study it, certain that He Himself, not an angel or a creature, is speaking with us in it.