From the God is Open Facebook page:

Douglas Gibson

Best conversation with Mormon missionaries at my door ever!
Subject? The Open View and the relationship between God’s knowledge and man’s free will.
I have come to the place in witnessing to people from different churches and fringe cults, in person, where my approach is to TREAT them like they are Christians whose interpretations may differ with mine on ‘some’ points.
This approach permits me to differ with them on an equal footing where they also still feel that I mean them no harm on any level. I find that they open up pertinent details that they otherwise would keep to themselves.

So these two young men came to my door and I met with them outside on our porch in keeping with my wife’s preferences which are actually wise, because many times our wives are wiser than we give them credit for.
After personal introductions and banter aside, they asked me my spiritual background. From this I brought up the open view. I explained what James White does when debating open theists that he always tries to compare us with Mormons.

One of the LDS whom I will call Alberta, since he is from Alberta, Canada, reacted to my claim that God experiences new feelings, new decisions, and can learn. Like a Calvinist, he gave the classical view that God cannot progress or learn anything new.
I asked Alberta if, in his opinion God was always like this. He affirmed his belief that God never had a beginning and that he is all-knowing in the sense of being outside of time and that the future is already ‘there’ in all its details for God to see.
So I asked him, “But as an LDS don’t you hold that God was once a man who through mormon teaching progressed to become a god?”
He affirmed that he holds this. And I asked him how that is possible if God never had a beginning and cannot learn anything new?
Alberta tried to turn the questions back on me to ask me if that was wrong to hold that God cannot experience new knowledge. He asked me why I think I am right.
So I took the opportunity to explain that if God knows and believes with certainty all future details and that Alberta would stop being a Mormon next month “for whatever reason”, then would Alberta have the freedom to do otherwise? He explained three times that he has freedom to choose and that this freedom is compatible with exhaustive foreknowledge.
Then when I tried to show that they are incompatible, he began accusing me of not having listened to him. I replied that I know what he was saying because he stated it three times. He then asked me what I thought he said without me putting a spin on what he was saying. Of course, I replied he was saying that he has free will to choose and that this was perfectly compatible with timeless foreknowledge.
So he couldn’t get anywhere when I proved I had heard him.
But I then added that his stating emphatically three times that the two things are compatible is not an argument.
He began getting riled up.

We got onto Adam and Eve and foreknowledge, next.
He affirmed that sin was part of God’s plan, that the cross was not a contingency plan whatsoever, and he also affirmed that Adam and Eve could not procreate since they were ‘innocent’ and could not procreate until they sinned.
So I explained that his views are virtually identical to Augustine and Calvin.
The other young LDS, whom I will call Washington because he was from Washington state, seemed very agreeable with what I was saying. He asked me about the test in Eden, and I distinguished between absolute certainty and conditional certainty, the idea that freedom entails risk, not certainty.
Alberta wanted to double down on what he said about God having timeless and unchangeable knowledge.

So I brought up his claim at the start that God was once a man who progressed to become God and that this implies progress in knowledge, but if one attains to changeless knowledge, that attainment is itself a change, and it implies a fixed future, the idea that the future is already definite.
Alberta was upset, saying that I was twisting his words and making him angry. He accused me of having called him a Calvinist. He was really livid. He DENIED having said that God never had a beginning, and then accused me of having put words in his mouth. (This Mormon was arguing FULLY like a Calvinist.) I nonchalantly replied that he denied having said that God never had a beginning and was accusing me of putting words in his mouth and twisting things, but that he was the one getting angry. I said this smiling and peaceful.
You should have seen how desperate and angry he was getting! He insisted that Mormons hold to the view that God has timeless and changeless foreknowledge. I also reaffirmed that I never called him a Calvinist, only that his ideas about foreknowledge and the decree for man to sin are Calvinistic.

I told him that I have had this conversation with other LDS missionaries and that they have universally agreed with me that timeless foreknowledge is incompatible with genuine free choice. Again, he doubled down with anger and I reminded him that James White constantly thinks to insult open theists like myself by comparing us to Mormons. He insisted that the other missionaries have it wrong.
So he again wanted to flip it and asked me why I thought I was right and he was wrong. (I love it when they ask that!)
So with minor interruptions I was able to explain from God’s warning Cain, Hezekiah’s repentance after God told him he was about to die, and from God’s changing his mind after he told the Ninevites that he would destroy them in forty days how these things are incompatible with free will unless God lied. But the real clincher was the example of Saul’s encounter with Samuel where the prophet revealed to the future king several future signs that would come to pass, with a command appended to the exhortation. I proposed that the reason why Saul’s disobedience to the command was not revealed to him as a prophetic sign was because commands in their nature are contrary to timeless foreknowledge. If God was outside of time, then why didn’t God reveal to Saul that along with the other prophetic signs of Saul’s choice to be king, that Saul would disobey and God would change his mind and remove the kingship from him?
Washington was very happy and impressed with my accounts of the Biblical narratives because he was presently reading through the Old Testament.

But here’s the icing on the cake. Alberta who was up to this point combative and visibly angry with me, began to profusely apologize to me, admitting he has a great problem with anger and wanted me to forgive him. He told me to check out the LDS website on ‘foreknowledge’ and I told him to give some prayerful consideration to the examples I provided from Scripture when he gets home.
Best confrontation with the LDS ever!

We also talked briefly about the cross being the way of salvation, for anyone who is looking to criticize this. We cannot please everyone.