In Malachi 3:6 God affirms, "I the Lord do not change." This is why Christian doctrine teaches that God is immutable—that is, unchangeable. The promise of this constancy and permanence in the nature and character of God has been deeply reassuring to many believers down through the ages. When everything else changes, we can remember the living God never fails or vacillates from anything that he is or that he has promised.
For this reason many are legitimately startled when they read that the Lord "was grieved" or "repented" that he had ever made man and woman upon the earth (Genesis 6:6). How can both the immutability and the changeableness of God be taught in the same canon of Scripture?
Scriptures frequently use the phrase "God repented." For example, Exodus 32:14 says, "Then [after Moses' intercession for the Israelites] the Lord relented and did not bring on his people the disaster he had threatened." Or again in 1 Samuel 15:11, "I am grieved that I have made Saul king, because he has turned away from me and has not carried out my instructions." Again in Jeremiah 26:3, "Perhaps they will listen and each will turn from his evil way. Then I will relent and not bring on them the disaster I was planning because of the evil they have done." (See also Jeremiah 26:13, 19; Jonah 3:10.)
The Hebrew root behind all the words variously translated as "relent," "repent," "be sorry" and "grieve" is nḥm. In its origins the root may well have reflected the idea of breathing or sighing deeply. It suggests a physical display of one's feelings—sorrow, compassion or comfort. The root is reflected in such proper names as Nehemiah, Nahum and Menehem.
When God's repentance is mentioned, the point is not that he has changed in his character or in what he stands for. Instead, what we have is a human term being used to refer—rather inadequately—to a perfectly good and necessary divine action. Such a term is called an anthropomorphism.
When the Bible says that God repented, the idea is that his feelings toward some person or group of persons changed in response to some change on the part of the objects of his action or some mediator who intervened (often by God's own direction and plan). Often in the very same passages that announce God's repentance there is a firm denial of any alteration in God's plan, purpose or character. Thus 1 Samuel 15:29 reminds us that "he who is the Glory of Israel does not lie or change his mind; for he is not a man, that he should change his mind." Yet Samuel made that statement the day after the Lord told him that he was grieved he had made Saul king (1 Samuel 15:11).
From our human perspective, then, it appears that the use of this word indicates that God changed his purpose. But the expression "to repent," when used of God, is anthropopathic (that is, a description of our Lord in terms of human emotions and passions).
In Genesis 6:6 the repentance of God is his proper reaction to continued and unrequited sin and evil in the world. The parallel clause says that sin filled his heart with pain. This denotes no change in his purpose or character. It only demonstrates that God has emotions and passions and that he can and does respond to us for good or ill when we deserve it.
The point is that unchangeableness must not be thought of as if it were some type of frozen immobility. God is not some impervious being who cannot respond when circumstances or individuals change. Rather, he is a living person, and as such he can and does change when the occasion demands it. He does not change in his character, person or plan. But he can and does respond to our changes.
Hard Sayings of the Bible.
Hope this stirs your thoughts to consider the awesomeness of God and how much higher His thoughts are than ours!