In case Clark Pinnock refuses to take theology lessons from Loretta Lynn, perhaps he might deign to do so from Luther. Here he is on Genesis 6:
But here another question is raised. Moses says: “God saw that all the thoughts of man were evil.” Likewise: “and He was sorry that He had made man.” Now if God foresees everything, why does Moses say that God saw only now? If God is wise, how can it happen that He repents of something He did? Why did He not see this sin or this corrupt nature of man from the beginning of the world? Why does Scripture attribute to God a temporal will, vision, and counsel in this manner? Are not God’s counsels eternal and ἀμετανόητα (Rom. 2:5), so that He cannot repent of them? Similar statements occur in the prophets, where God threatens punishments, as in the case of the Ninevites. Nevertheless, He pardons those who repent.
To this question the scholastics have nothing else to reply than that Scripture is speaking in human fashion, and therefore such actions are attributed to God by some figure of speech. They carry on discussions about a twofold will of God: “the will of His sign” and “the will of His good pleasure.” They maintain that “the will of His good pleasure” is uniform and unchangeable, but that “the will of His sign” is changeable; for He changes the signs when He wishes. Thus He did away with circumcision, instituted Baptism, etc., although the same “will of good pleasure,” which had been predetermined from eternity, continued in force.
I do not condemn this opinion; but it seems to me that there is a less complicated explanation, namely, that Holy Scripture is describing the thinking of those men who are in the ministry. When Moses says that God sees and repents, these actions really occur in the hearts of the men who carry on the ministry of the Word. Similarly, when he said above: “My Spirit will not judge among men,” he is not speaking directly of the Holy Spirit as He is in His own essential nature or of the Divine Majesty but of the Holy Spirit in the heart of Noah, Methuselah, and Lamech, that is, of the Spirit of God as He is carrying on His office and administering the Word through His saints.
It is in this manner that God saw human wickedness and repented. That is, Noah, who had the Holy Spirit and was a minister of the Word, saw the wickedness of men and through the Holy Spirit was moved to grief when he observed this situation. Paul also similarly declares (Eph. 4:30) that the Holy Spirit is grieved in the godly by the ungodliness and wickedness of the ungodly. Because Noah is a faithful minister of the Word and the mouthpiece of the Holy Spirit, Moses correctly states that the Holy Spirit is grieving when Noah grieves and wishes that man would rather not be in existence than be so evil.
Therefore the meaning is not that God from eternity had not seen these conditions; He sees everything from eternity. But since this wickedness of man now manifests itself with the utmost violence, God now discloses this wickedness in the hearts of His ministers and prophets.
Thus God is immutable and unchanging in His counsel from eternity. He sees and knows all things; but He does not reveal them to the godly except at His own fixed time, so that they themselves may see them too. This seems to me to be the simplest meaning of this passage, and Augustine’s interpretation differs little from it.
Martin Luther, Lectures on Genesis: Chapters 6-14, vol. 2, Luther’s Works, ed. J. J. Pelikan, H. C. Oswald & H. T. Lehmann (Saint Louis: Concordia Publishing House, 1999, c1960), Genesis 6:5-6, p. 43-44.