Theists: How can predetermined fate and free will coexist?

[Neo-Scholastic]

Under the eternalist theory of time, the idea is that God is fully present across all of time. As such past, present and future are all present to Him. That means that He doesn't know what you are going to do now because He already knows what you did tomorrow. Kind of a mind-bender but then again so is retro-causation.

Under the presentist or block theory of time, God knows only what it is possible to know. The future does not exist in either of these theories. No one can have knowledge of something that doesn't exist. Therefore, it is not logically possible for God to know the future.

Under the presentist theory that creates an interesting puzzle since the past is said to no longer exists. So by the same logic as above God could not know the past either. The work around for this is that He could infer the past from the state of the present. Which creates another puzzle. Could He not also infer the future? That depends on whether volition can only move from a present state forward. But that creates yet another puzzle. How can one truly say that past and future do not exist if we're moving from one to the other? It should be noted that it doesn't prevent Him from acting in such a way that certain but not all events are inevitable outcomes.

I guess my point is that everyone thinks they know what time is until they start thinking about it.