I also do believe as well that spirit can navigate time, looping back and choosing a different path at previously navigated junctions, or even switching (jumping?) to any path throughout the block universe. Whatever ‘present moment spot it lands on’ will have its past and future light cone associated with it to limit its perception of its potential past and future experience. Timelines (or causality lines?) fan out into the past and future bounded by those past and future cones, but all such lines, these rays of light, pass through the origin of that present moment. Yet it may seem to spirit, as it looks back into its past light cone, that it has probably been on one of those linear timelines all along. When spirit looks into the future causality cone it sees many different chains of cause and effect with perceived differing probabilities, which it must navigate to create one future timeline. Of course as soon as it takes its next action, it is on a different present moment within time, with different (even if only slightly) past and future cones, and all those future probabilities are reexamined, as well as the new possible past timelines that intersect with its new present moment. And so it goes, hopping from present moment to present moment though the block universe, navigating its chains of cause and effect and becoming one timeline as it plays its multidimensional game of “connect the dots”, known as “this lifetime”.

Time in this block universe is just another direction like space. Time and space actually are believed to “switch roles” within the ‘interior’ of a black hole. Spirit however, at least it seems for this life experience we are living, is limited in the direction of time by the second law of thermodynamics. It can only take and experience actions in the direction of increasing entropy. This is what defines the direction of the light/causality cones, at least unless it decides to navigate (jump/loop) through the fifth dimension to a new point in four dimensional spacetime

One clue to this ability of spirit to navigate anywhere through the multidimensional block universe is the density of the vacuum energy of space. Theoretically it should be infinite. Mathematically infinities cause problems so physicists “hack” a bit off the top to make it finite, something they can work with. But I think the density is in fact infinite, because the block universe is both infinite and eternal and spirit has direct access to any of it, eternally available to create its reality within (its ‘timeline’ or ‘causality chain’), for its next present moment. In other words, every point in spacetime is in fact connected to every other point, or more accurately they are all the same non or zero dimensional point, a singularity sitting conveniently on the end of its spiritual nose. Which is why entangled matter appears to react instantaneously regardless of distance, and why waves in the double slit experiment appear to go backwards in time (even billions of years back), so as to appear as particles, when the scientist decides to find out where they were after the experiment is over. Spooky action at a distance is not spooky if you understand that there really is no distance, we are just ‘imagining’ or creating it within consciousness. BTW, this is also, I believe, why a true medium will tell you that it makes no difference in how far someone is away from them regarding whether they can sense them.

Of course when physicists try to measure the vacuum energy they get a very small number, instead of infinity or something very large. This makes some sense as analogous to what happens when one goes to make a measurement of the quantum wave. The infinity of probabilities represented within the quantum wave function, all those different Schrodinger cats and green birdies, ‘appears to collapse’ into one limited picture of reality. Yet I expect that this collapse only occurs in the perception of the observer (and that which is entangled with it). The quantum wave function and its infinite probabilities remains (has and will for eternity), containing and making available to spirit, all of space and time. Other non entangled observes are free to perceive an entirely different collapse, leading to a different world for them. There are many worlds superimposed within the quantum wave function, probably infinitely many worlds for spirit to choose from. This so called ‘collapse’ is just the perception of spirit as it takes an action (in the wider physics sense of that word) and goes from one present moment into the next.

So in both of these phonomenon, the ‘collapse’ of the wave, and the ‘vacuum catastrophe’, we see IMO, a clue to a boundary or eternally unfolding horizon of sorts between the infinities of energy and probability represented by the non-physical quantum wave function, and the finite energy and one ‘physical’ outcome of the perceived reality constructs within the conscious observer. The infinite myriad of forms are eternally emerging from the other side of that horizon. From the formless boundless world of unmanifested probabilities, into the world of spacetime and matter created by and within consciousness. The fundamental essence of this infinite source is a mystery to all who occupy this side of the boundary, we only see its manifestations, those manifestations spirit desires to see and experience. As soon as we seek to imagine what is on the other side of that horizon, we manifest limited forms within our own consciousness to represent it (e.g. a Quantum Field). The more we manifest, the more we limit its infinite expression and the further from its depth, its mystery, and into its fringes we go. Moving across that horizon that separates the finite formed from the infinite formless.

Spacetime and matter is something consciousness creates within, as a part of its reality, to allow it to go exploring in the matrices of cause and effect. All of space and time, past present and future, all of when and where, exist within a singularity. It is consciousness that stretches it out into the four dimensional illusion, within itself. It then goes about creating and observing the matter and forms within it to explore and observe cause and effect, writing and acting out dramas to represent those subjectivities that it is seeking to understand. Consciousness creates what, when, and where in its search to find out why, its search for meaning, its search to know and understand the essence of God. Physics just concerns itself with the how. Shiva dances Maya into the perception of existence, from nothing, beginning his dance with one apparent 'big bang'. The echo of which reverberates through all of manifested spacetime as the cosmic background radiation, and can be heard in the sound of the sacred Om.

The OP asks why does God not show him or her self? God is eternally present and seen in all things, and in nothing at all. The eternally unfolding finite and limited experience of life, originating from the unlimited infinite mind of God, and explored by the limited mind of spirit, is one way that spirit learns to recognize itself, to recognize and know God, in nothing, in all things, and in everything as one.