It is a well known problem. The book of Exodus describes God hardening Pharaoh’s heart on several occasions. For example,
“But the Lord hardened Pharaoh’s heart and he would not listen to Moses and Aaron, just as the Lord had said to Moses.” (Exodus 9:12)
The problem is obvious: if God is perfectly good, why would he act upon the will of a human being to lead that human being to engage in an act of evil?
A common response among apologists and pastors is that Pharaoh also is described in the text as hardening his own heart (e.g. Exodus 9:34) And so, as the saying goes, God merely affirmed Pharaoh in his course of action.
But this isn’t really a response. Consider, the underlying issue can be stated like this:
No Determination to Evil Principle (NDEP): “A perfect being would not override a person’s will with the end of ensuring that the person chooses an evil course of action.”
It certainly seems to me that something like NDEP is the underlying ground for objection. It also seems to me that something like NDEP is very plausible.
So what is gained by saying half of the time Pharaoh hardened his own heart? That doesn’t change the fact that NDEP is violated every time God hardens Pharaoh’s heart.
Think of an analogy. Imagine that Dave sniffs gasoline. You then discover that Dave sniffs gasoline because Dr. Nefario put a microchip in his head and controlled him, thereby determining him to sniff gas. So you confront Dr. Nefario, outraged. And he replies: “Ahh, but I only caused Dave to sniff gas about half the time. The other times he chose of his own free will to sniff gas.”
The fact that Dave chooses on his own to sniff gas half the time doesn’t change the fact that it is unconscionable for Dr. Nefario to cause him to sniff gas the other half.
What is more, every time Dr. Nefario causes Dave to sniff gas, he habituates a behavior in Dave which makes it harder for Dave to do refrain from sniffing gas when his free will is unimpeded by Dr. Nefario.
By the same token, the fact that Pharaoh hardens his own heart doesn’t reduce the problem with God hardening Pharaoh’s heart. What is more, the more God hardens Pharaoh’s heart, the more it would appear that God habituates patterns of rebellious behavior in Pharaoh which would make it more difficult to refrain from hardening his own heart when his free will is unimpeded by God.