Ligonier Ministries has posted a collection of Reformation Day resources that includes several articles and free MP3 lecture downloads by Dr. R.C. Sproul.
If we want reformation, we have to start with ourselves. We have to start bringing the gospel itself out of darkness, so that the motto of every reformation becomes post tenebras lux — “after darkness, light.” Luther declared that every generation must declare freshly the gospel of the New Testament. He also said that anytime the gospel is clearly and boldly proclaimed, it will bring about conflict, and those of us who are inherently adverse to conflict will find it tempting to submerge the gospel, dilute the gospel, or obscure the gospel in order to avoid conflict. We, of course, are able to add offense to the gospel by our own ill-mannered attempts to proclaim it. But there is no way to remove the offense that is inherent to the gospel message, because it is a stumbling block, a scandal to a fallen world. It will inevitably bring conflict. If we want reformation, we must be prepared to endure such conflict to the glory of God.
—Dr. R.C. Sproul