In spiritual and divine things the unregenerate person's intellect, heart, and will are utterly unable, by his natural powers, to understand, believe or think. They are entirely dead to what is good. They are corrupt. He is sin's servant (John 8:34) and the devil's captive, by whom he is moved (Ephesians 2:2; 2 Timothy 2:26).
We know that the wisdom of this perverted world is only foolishness before God.
Mankind's reason or natural intellect does still have a dim spark of the knowledge that there is a God. It also knows about the doctrine of the Law (Romans 1:19-21, 24, 32). Yet it is so ignorant, blind, and perverted that even when the most ingenious and learned people on earth read or hear the Gospel of God's Son and the promise of eternal salvation, they cannot by their own powers perceive, understand, or believe and regard it as true. They want to understand these spiritual things with their reason. Before they become enlightened and are taught by the Holy Spirit, they regard all this only as foolishness or fictions.
"The natural person does not accept the things of the Spirit of God, for they are folly to him." (1 Cor. 2:14)
"For since the world did not know God through wisdom, it pleased God through the folly of what we preach to save those who believe." (1 Cor. 1:21) (paragraphs 7-10)
Condensed from CONCORDIA: THE LUTHERAN CONFESSIONS, copyright 2005,2006 by Concordia Publishing House. Used by permission. All rights reserved. To purchase a copy of CONCORDIA, call 800-325-3040.