If one views God as indifferent, leaving the mechanisms of nature to run on automatic, harsh and cruel as they may, that would explain a great deal.
A universe that appears to be on autopilot is just as well explained by leaving gods out. And yes, the world is so much more comprehensible from that perspective. The belief in a tri-omni god that judges and punishes creates philosophical problems like the one this thread is about - is free will compatible with omniscience? - that only exist for those committed to concept that man has free will.
In the case of the Abrahamist, whose god fits the above description, he needs his god to be all-knowing and fair at the same time, but that's not possible if one describes a god that foresees everything before he creates it and then punishes its creation for being whet it made them and always knew that they must be. And so he is forced to simply say that man has free will anyway even if that is incompatible with perfect omniscience. He says that they ARE compatible and calls that position compatibilism, but that doesn't help the argument.
But for the atheist, there's no insurmountable problem here at all. Maybe there is free will and the universe is not compelled to unfold one way. Or maybe the opposite is the case. It may be difficult to decide between these, but they're both coherent positions. The theist who wants to keep both omniscience and free will is forced to take an incoherent position and simply insist that it's possible anyway without an argument, or with spurious arguments:
The main point is that God's foreknowledge is not the cause of anything that happens, including our choices.
Why do you want to make that point? Nobody seems to be arguing it. Suppose this god exists and does know the future perfectly. Suppose it could download that knowledge to you or me. Now we know the future perfectly, but we are not claiming to be the cause of that future - just that it IS caused deterministically.
According to Abrahamic religion, unlike for you and me, that god is ALSO the cause of what happens. But none of that is relevant to whether free will and omniscience are compatible. It's a deflection from that discussion that doesn't help resolve it.
knowledge is not causation
There it is again. This is standard in the toolbox of those making your argument.
thus we do have free-will.
This does not follow from your last comment.
Even atheists argue for compatibilism.
That doesn't strengthen the argument. Nobody should be arguing for compatibilism. It indicates to me that such an atheist has an irresistible intuition that his will his free while understanding that even quantum indeterminacy cannot generate free will. He has the same problem as the Abrahamic theist, but his barrier is not an ideology, but rather, a psychological state that he cannot transcend.
Let's take a moment about what we're claiming is the case when we say that man has free will. Most people mean that they have desires and if able, will freely make them reality. Thus, my hypothalamus detects relative dehydration and sends a message of thirst to the subject of consciousness, which then goes for a drink. If that's what you mean by free will, THAT is compatible with determinism, but it's what some call the illusion of free will. We don't know whether we could have had any other will, nor whether we could have acted any other way.
But if we mean that the self is the author of that desire rather than a passive recipient of unseen brain circuits like the hypothalamus and dorsomedial prefrontal cortex, and that it actually could have chosen otherwise rather than that it feels like it could have - that's what I mean by free will - then we may not have that. That may not be possible.
But some will simply insist that they have free will anyway because their will feels free and because their theology or intuition cause them to insist that free will must exist even if they also believe a god knows every desire and every choice before they do.
We may in fact be those robots that many theists say that their god doesn't want and didn't create. If so, we're blissfully unaware of that as we deterministically go about fulfilling a preordained destiny feeling fully free and feeling as if we are the author of our desires and could have acted otherwise. If that's how reality is, then I'm good with that. But the Abrahamist cannot accept that for ideological reasons, and apparently, neither can the atheistic compatibilist, apparently because his intuition rejects the possibility that his will might not be free.
mathematically one could perceive of a 4D being while we are 3D (dimensional). This is just to conceptualize God's view of our time.
This is just an explanation for omniscience, not an argument for the coexistence of free will.