Being someone who is intrigued by these concepts, I think it's a fun excercise to comtemplate it as long as I don't constipate it. It's easy to overthink it and end up in sci fi land.
If it wasn't reaL in some sense, then in all fairness we shouldn't be judged by what we do in it. God creates, therfore he makes things from other things or from nothing, or what we may think of as nothing. He made this and sits outside of it looking in and introduces things as He sees fit into it. It's plenty real to every creature who inhabits it. We might call it our "reality" because in every sense we are aware it is real.
You sound like an atheist here. The atheist sees that he already has life...why does he need to go to Jesus for life? Jesus is the Way the Truth and the Life. So many modern believers are really just unbelievers since they see the material world as the only platform that is available to us. For these...seeking the kingdom first...has to mean we are looking to die as quickly as possible...in order to partake of the afterlife as per our religious assumptions.
Of course this world is real to us. And that is all there is until one is born into the kingdom realm of the Spirit. We are not to love this world or the things of this world. So then where is our love to take place?
The gospel is an invitation into His eternal realm. And this is meant for now while we are still in these mortal bodies. Waiting for a physical death for intimacy with God....to know Him...is the error of the agnostic and the atheist.One of my questions would be, does he segway this into the rest or are we compartmentalized? It's hard to tell. I'm nothing like God other than a representation in a crude way of His 'image'. His thoughts are so far above mine it's embarrassing and not worth a mention.
The givens are that He knows the beginning from the end, much like a watch maker who tediously makes a precision watch he knows everything about it and he has predicted every outcome. God is sovereign. If someone is playing with His stuff he is aware of it. There is possibility that the other side has enough info to play with it, but only as He allows. Anything they would do will be like trying to scratch a diamond, yet I think they can influence it. Jesus has dominion over heaven and earth, as in all the forms of heaven and anything inbetween.