PAUL always supports his teaching from Scripture, and this is what he is doing here. He has affirmed that the message of the cross is foolishness to those still in the world and as a result are still perishing, and on their way to eternal destruction in hell. He now refers to Isaiah 29: 14 to authenticate this doctrine. In this verse from Isaiah we read what God has declared, which is that he will destroy the wisdom of the wise, and will frustrate the intelligence of the intelligent.
What does this mean? It does not mean that God will destroy the intellects of all the intellectuals in the world. When we observe the world we can see this is manifestly not true. Wisdom in the world, in all matters of worldly knowledge, is increasing all the time, and at a very fast rate. There is discoveries in medicine, in science, in space exploration, in electronics, and much more, and this is continuing all the time. This worldly wisdom is not destroyed or frustrated by God. God may and does control it in his common grace over the world, so that man's sinfulness may not bring about complete disaster, but God does not prevent mankind increasing in knowledge concerning the world.
So what does this declaration of God in Isaiah describe for us? It describes the fact of God's judgement on sin and sinfulness in mankind, so that human beings cannot, in their own strength and wisdom, seek and know God. Human beings, by their own wisdom, can search out and know all kinds of knowledge, but the knowledge of God is impossible for fallen and sinful humanity to know by their own wisdom and searching. The bible can be studied, and its contents absorbed and remembered; the doctrines of the bible can be intellectually understood; people can discuss theological matters, and come to conclusions; but in all their deliberations they are totally unable, by their wisdom, to know God and be reconciled to God. The reason is that their human fallen wisdom always rejects the truth and refuses the truth.
The Bible contains the revelation of God as to how we can know him and be reconciled to him, but its saving meaning can only be made known to human beings by God himself by the operation of the Holy Spirit. For man to understand the bible and know God, he must renounce his own wisdom and submit totally to the wisdom of God. This fact can be seen by the fact that in all searching for God by mankind by his own wisdom, there is a total reliance on human effort and works. In this way human intellect questions the authority and veracity of the bible testimony, and finds the message of the cross offensive to human pride. Human beings, in seeking to gain God's favour by their own moral attainment, come to God believing they have a right to God's blessing because of their moral attainments, and are unable to appreciate how far below what God requires their attainments are.
What is the way forward? How can we know God? How can we read the bible and attain the wisdom of God? The first thing we must do is to humble ourself before God and renounce our own human wisdom, and throw ourself on the mercy of God. This requires us to humbly and with true repentance acknowledge that we are sinners before God, and cry for mercy with the time old prayer �God be merciful to me a sinner�. When such a prayer comes up to God, then God hears, and for Christ's sake leads us to the knowledge of how we can be reconciled to him and know him.
In this frame of mind the Scriptures become a new book. What seemed so unreasonable before now becomes the wonder of God's grace. God's wisdom is given to us, and we are made able to receive it with faith and joy. The truth is that the humble seeker of the truth of God is rewarded by God with spiritual sight and understanding.
In Isaiah 61 which Jesus reveals is a prophecy concerning himself in Luke 4: 21, we are told that Jesus was anointed with the Holy Spirit to preach the gospel to the poor. The poor are the poor spiritually, who are unable to appreciate the good news because of they are in prison to Satan, blind to spiritual truth, oppressed by sin and sinfulness. All human beings are in this condition of spiritual blindness from birth. This blindness is because of deadness of soul. It means we can't hear God and spiritual things with understanding. When we humbly cry for mercy God bestows upon us new life. We are raised from the dead spiritually. The eyes of our understanding are opened. Our deaf ears, which means our inability to hear truth and understand it, are opened; and the truth of the grace of God to sinners through Christ, and his work for us, is heard with understanding. By faith through grace we are born again, and receive the privilege of being God's children, and knowing God as our heavenly Father.
The world does not accept the truth about their human wisdom with regard to knowing God and being found in favour with God. If they are told that God is working against them while they are seeking him by their own wisdom, they will laugh at such an idea, and regard it as preposterous. It is impossible to know God while we are seeking him in our own wisdom, because God will frustrate such thinking and destroy such wisdom.