From the Geneva Institute for Reformed Studies in an article entitled “Does God Repent of Things He Has Done?”:
Genesis 6:6-7 is a prime example, “And the LORD was sorry that He had made man on the earth, and He was grieved in His heart. So the LORD said, ‘I will destroy man whom I have created from the face of the earth, both man and beast, creeping thing and birds of the air, for I am sorry that I have made them.’ But Noah found grace in the eyes of the LORD.” (NKJV)
The old King James Version translates verse 7, “And the LORD said, ‘I will destroy man whom I have created from the face of the earth; both man, and beast, and the creeping thing, and the fowls of the air; for it repenteth me that I have made them.’ ”
Did God regret something he had done? Did he really repent as if he had made a mistake? Did God have to change his plan from what he had formerly wanted it to be? If so, then he is not the God we read about in the rest of the Bible. A careful study of these passages removes the apparent conflict.
First we need to take a look at the larger context. What do clear Bible passages teach about God’s nature?
God’s nature is “immutable” (he does not change).
The answer to Westminster Shorter Catechism question 4 is, “God is a Spirit, infinite, eternal, and unchangeable, in his being, wisdom, power, holiness, justice, goodness, and truth.”
If this is true, God can never regret, make errors, or change his plans. He answers to nothing greater than himself, therefore he is perfect and needs no improvement. God’s knowledge is perfect. It includes all things that ever will happen, there can be no reason to ever change or modify his plans.
Notice the appeal to a catechism. The remainder of the article lists various Bible verses that “contradict” God’s repentance, then offers an alternative meaning for “repent”. For context, click here.
See also, Calvinist Lies by Christopher Fisher which talks about the Hebrew use of the word repentance.