. But why does exist our Universe at all? Well, what does mean "exist"?
. The viewpoint here is that ALL math constructs do in the same sense physically "exist". Also inconsistent math constructs do "exist". Many simple math constructs have a complicated outcome, for example the Mandelbrot Set, this is a two-dimensional set with a relatively simple definition that exhibits great complexity, especially as it is magnified. The set is defined in the complex plane as the complex numbers c for which the iteration of z starting with z=0: z*z + c ==> z , remains bounded. i.e. in which z does not diverge to infinity. ^ A math construct with a bit more advanced definition might describe already more typical aspects of our world ...
. Any part of any math construct that has a structure resembling a human (or animal) brain will experience consciousness. Compare Wikipedia "Mathematical Universe Hypothesis".
. Because the structure supports "self-aware" substructures, it must be a highly advanced math construct. Indeed the Universe we ourselves live in has an intricate structure. For example to us as conscious substructures, the view of microscopic events look different from different spots, and look as being described by "waves". But still, the system has a purely mathematical structure.
. So our brains are substructures of some sufficiently advanced math construct. Our decisions we make as a Living Creature (and maybe as a God) coincide with the rules and effects of the math construct, this is no contradiction, it are just two different ways of interpreting the decisions. One could compare this duality with the (quite different) duality in quantum theory, in that one can describe physical matter as waves but also as particles.
. There is still a problem with "ALL math constructs" . The rules of our world extended with some Divine Revelations is also a math construct. Why dont we experience living in that world? Possibly the Probability of a math construct plays a role also, in that math constructs with simple rules are far more probable than math constructs with more complex rules?... How the probability of a math construct is established, that is unclear, and possibilities should be investigated.
. Maybe also FINITE math constructs are far more probable. Indeed it seems that our Universe has a FINITE (though very very large) number of constituents, and there is a minimum non-zero length-measure (Planck-length) etc.
. But OK, the viewpoint is that ALL math constructs do in a certain sense "exist". Our Universe is one of these math constructs. It is a construct in which by chance the parameters are such that there is an atom (carbon) that can form complex structures, which makes possible the development of elaborate Life. The substructures can follow random paths. Please realize that tiny variations in a structure can within the structure grow out to big and elaborate phenomena. E.g. one turn of a flies wing in Brazil can grow out to a huge tempest in USA.
. My conclusion: Our Universe with Life is there by chance. There will be myriads of other Universes, with other physical laws etc., without any form of Life. Though there will still be very many Universes WITH intelligent life of some sort.
. Also one should realize, life on our good earth could just like that be extinguished, maybe by an all-out nuclear war or by another worldwide disaster. There will probably be no God that can inhibit it. We as inhabitants of the earth must try to arrange that this will not happen.