Scott Diekmann gives the following quote from Walther over at his blog. Let's consider it for a moment or two.
…In recent times people actually think one has to make additions, that church doctrine evolves gradually and grows in scope as the church grows older. [They maintain that] in apostolic days, so to speak, the church was in its infancy, but that now it is gradually maturing into full adulthood in Christ [cf. Eph. 4:13]. But it is not doctrine we are to develop, so that new doctrines are introduced, as among the newer theologians; rather we are diligently to use our reason, so that we truly know and understand the doctrines the church has always had. It is not our task to develop new doctrines, but to master our comprehension of the doctrines already revealed and always known to the church. God has by His grace enabled us here in America to realize that it is and can be neither man’s enlightened reason nor anything else, but only God’s Word, that is to be the source of all doctrine. As long as we cling to it, we will be unshaken, as on the rock [cf. Matt. 7:24-25]. Let us gratefully cling to it, refusing to let Satan drive us away. (brackets in original)
C.F.W. Walther, Essays for the Church, Vol. 1 (St. Louis: Concordia, 1992) 157.
Now, this quote drives to one of the main differences between Lutherans and Protestants/rationalists. We do not try to create new doctrines - we seek to understand the teachings of our Lord more and more so. We do not try to make the Church respond and speak to the culture - we seek to see how our culture might blind us to the truth of the Scriptures (and thus what from our own culture we ought to reject and avoid). We aren't trying to increase our information, we aren't trying to create knowledge - we are trying to grow in knowledge that has been know. We don't make new doctrines, we seek to ensure that doctrine remains pure.
Now, this doesn't mean blind obedience to the opinions of those who came before us -- there are points where I will disagree with Luther (shock!) and even points where many disagree with Luther that I don't think he was off on (horror!). Same with Augustine, or Cyril of Alexandria, or Walther. They had fantastic insights, and many things they knew and expressed well. We learn, we see them point to Christ. . . but keep our focus upon Christ. We learn, we grow, we think and ponder and meditate.
Just learn, without pride, without arrogance - just learn.