Daily Luther: Nothing But the Word!
Faith must have absolutely nothing but the Word on its side and must permit no subtle argumentation or human ideas in addition. Otherwise it is impossible for faith to be retained and preserved. For human wisdom and reason cannot progress beyond judging and concluding in accordance with what it sees and feels or with what it comprehends with the senses. But faith must transcend such feeling and understanding or make its decision contrary to these and cling to whatever the Word submits. Reason and human competence do not enable faith to do that, but this is the work of the Holy Spirit on the heart of man. Otherwise, if man could comprehend this with his reason, or if he were to resolve this in accordance with what is and what is not consonant with his reason, he would not need faith or the Holy Spirit.
Martin Luther, Luther’s Works, Vol. 28: 1 Corinthians 7, 1 Corinthians 15, Lectures on 1 Timothy, ed. Jaroslav Jan Pelikan, Hilton C. Oswald and Helmut T. Lehmann, 1 Co 15:1–2 (Saint Louis: Concordia Publishing House, 1999).