Bruce Ware objects that God’s test of Abraham just could not have taught God what Open Theism claims that it has taught God. Ware’s third reason for this:

Third, given the openness commitment to the nature of libertarian freedom, God’s test of Abraham simply cannot have accomplished what open theists claim it has.

…

According to these openness advocates, Abraham’s testing proved to God now that Abraham was a faithful covenant partner who, therefore, fore, could be trusted to be faithful in working with God in the fulfillment of God’s covenant purposes. But since Abraham possesses libertarian freedom, and since even God can be taken aback by improbable able and implausible human actions, what assurances could God have that Abraham would remain faithful in the future? One realizes how transient the “now I know” is for God. As soon as the test is over, another test would seemingly be required.

And notice, too, an interesting dilemma faced in the openness understanding of Abraham’s testing. At best, what God could come to know, on openness grounds, is whether or not Abraham’s passing the test demonstrated the continuation of a pattern of behavior that would render Abraham’s future faithfulness more probable. But of course, on the one hand, if Abraham’s passing of this test confirms further a pattern tern of faithfulness Abraham had already demonstrated in his life of trust and obedience, then it could not be literally true that in this test (i.e., the test of the sacrifice of Isaac) God learned now that Abraham feared him. On the other hand, if Abraham passed this test in striking contrast to a pattern of his previous unfaithfulness, why would God then conclude that Abraham would remain faithful in the future, even when he had passed this test, given his previous pattern of disobedience? Either way, whether Abraham had previously demonstrated a pattern of faithfulness fulness or not, the singular and transcient nature of this specific test demonstrates that what openness proponents claim God learned simply could not have been gained.

Bruce A. Ware. God’s Lesser Glory: The Diminished God of Open Theism (Kindle Locations 587-600). Kindle Edition.

Ware offers a double edged third critique:

1. God cannot have gained any certainty from the test.
2. God should have already seen the pattern.

Let the reader imagine a perhaps analogous scenario. A wife wants to know if her husband is faithful. She knows that he has been faithful in the past, but really wants to see if he holds true when presented with the opportunity. This will impart new knowledge: a new situation in which his faithfulness has never yet been tested.

She enlists a friend of hers to approach him. Her friend is attractive and seductive. She arranges for her friend to proposition her husband. After an attempted proposition, the husband declines. The wife then calls her husband, exclaiming “Now I know that you are faithful to me.”

Are Ware’s objections valid? Does the husband’s past faithfulness make this new data point obsolete? Or, is this a useful and necessary data point in understanding who her husband truly is?

Can one now object to the wife’s statement that “now she knows that he will be faithful” because he still has the free will to become (at some point of time) unfaithful. Or maybe she should not be able to make that claim because she just didn’t hit the right variables (maybe her husband prefers blondes over brunettes and the wife has to exhaust infinite numbers of test to truly know anything).

Ware’s objections seem unreasonable. Even with a history of data points, a new data point might yet be informative, especially when it is designed to cover a point that no previous data point has covered. Additionally, a specific test can act as both a proxy for other similar tests and as a proxy for true knowledge. That truth can be proclaimed as such.

See also:

https://godisopen.com/2016/03/17/apologetics-thursday-erickson-on-genesis-22/