If God is confined solely to the present then He cannot foreknow anything only make projections based on His past experience and His assessments of present conditions. Some things He would be fairly certain of perhaps to the extent of 99%. This level of certainty might include natural events. For instance He would be able to predict when an asteroid would strike Mars because He can see it moving in space. Whether or not the same asteroid will strike earth is another matter since it might be that free agents (if they were aware of the impending catastrophe) might be able to prevail upon Him to change its course. The same might be said of what He Himself would do, if the decision He makes is unilateral and is not conditioned on the choices of people.
The decisions men will make and the outcome cannot be absolutely known, only predicted. God might be able to make a good estimate based on His “profile” of them but the likelihood of these predictions are highly uncertain even when a persons MO has been very consistent. The certainty of what men will do becomes less and less accurate the further into the future such projections are made. This is because as time passes a single unpredictable free agent interact with countless other equally unpredictable The possible choices man might make increases exponentially with the passage of time passes. It is like an expanding chaos system. Therefore the Lord who cannot foreknow can only forecast like the weatherman. It is hard enough for the weatherman to predict what the weather will be in the short run. It is impossible for them to know today what the weather will be like tomorrow or in 2000 years.
Open Theism’s denial of foreknowledge is falsifiable, however. If there is an occasion where God absolutely knows what men will choose to do in the distant future then God has the attribute true foreknowledge. The following is such an example. When the disciples asked Jesus when He was coming back The Master said that no one not even He that day and hour This was a secret known only by the Father. If Open Theism were true even the Father could not know anything so specific as the day and hour. God could for whatever reason pick a day and hour. He could say that the Son of Man will return to earth 6/6/2066 at 6:66 am CST. The probability of this happening would be 100% as long as His prediction was not conditioned upon the acts of free agents. This, however, is not the case.
One of the signs that immediately precedes His coming is the is the so called Great Falling Away. Now there have been many times in history when the Church has gone through tribulations and in those times many departed from Christ but THIS particular time of tribulation and apostasy would differ from all others in intensity and pervasiveness.
Matthew 24:10 At that time many will turn away from the faith and will betray and hate each other, 11 and many false prophets will appear and deceive many people. 12 Because of the increase of wickedness, the love of most will grow cold, 13 but he who stands firm to the end will be saved (NIV)
2 Thessalonians 2*Concerning the coming of our Lord Jesus Christ and our being gathered to him, we ask you, brothers and sisters, 2*not to become easily unsettled or alarmed by the teaching allegedly from us—whether by a prophecy or by word of mouth or by letter—asserting that the day of the Lord has already come. 3*Don’t let anyone deceive you in any way, for that day will not come until the rebellion occurs and the man of lawlessness (the antichrist) is revealed, the man doomed to destruction. 4*He will oppose and will exalt himself over everything that is called God or is worshiped, so that he sets himself up in God’s temple, proclaiming himself to be God.
.
“Falling away” is a human choice which according to Open Theism God cannot predict; especially that far in advance. I suppose it could be argued that God could ensure that the siapostasy would happened around the scheduled event by withdrawing His influence and let the Devil have his way. This is inconsistent with the character of God is good and desires that all men come to repentance. One would suppose that He would do everything possible to prevent this. Who knows? Perhaps if God sent another Jonah the world would repent as did the Ninevites and the judgment would be averted. God can, after all, change His mind.
Signs are intended to indicate that something is ahead not that it might be. If a road sign says “bridge out” I would expect that if I kept driving I would find it to be so. If the Army Corps of Engineers had removed the threat and left the sign up then the sign is misleading. In the same way if any of the “signs” Jesus mentioned did not take place all that was written of them would be abrogated along with any certainty that Jesus would come on a specific “day and hour.” Within the paradigm of Open Theism end time events are one of many possible futures in a world that does not and may never exist. He might as well have said the signs MIGHT happen.