I promised to shed some light over my theist philosophy, so here goes.
Rather than saying directly "God exists", it tries to prove it the opposite way: "It's impossible for God to not exist".
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For me the brain represents the material link between the body and soul. DNA is also material, and materia in itself doesn't have the intelligence to create life and the perfect balance and symbiosis in the ecosystems.
Soul is more important than materia for the existence as a whole. If there was not even one soul ever, not even time or the void alone that the universe floats in would have existed because there would have been nothing and no one to detect their existence, and thus they would have existed for nothing.
The existence and continuity of souls is thus a necessity for existence of everything else. It gives universe a reason and a meaning.
I do appreciate science as it tries to feed our hunger for knowledge, which is definitely a noble goal. But Big Bang theory and the evolution theory are still just that theories, because they don't have all the supportive evidence to make them 100% (of the) fact yet.
The Big Bang theory only starts from the point where the materia already existed, and does not much comment on where the energy came from to create the materia into the void for the Big Bang to happen later on. On top of it, no astronomer is able to explain where the center point of the great explosion located.
For the evolution theory to work, there must be a mechanism in living cells which adds more DNA to the DNA chain. But no one has been able to prove that yet, and mutation only changes or swaps DNA, it doesn't add it. Scientiests are also unable to explain the birth of a nucleus in a cell.
Scientists do admit that there must be an organizer which keeps all the materia in proper order and the nature on this planet in balance, but doesn't straight out name the organizer as a designer or soul, or in other words, God. That's because science refrains to comment on beliefs or religion to stay as neutral as possible, and only examines the observable, material world.
Refraining from commenting the subject doesn't mean, however, that science denies the existence of souls, or God. That's what people choose to do, not science itself.
Besides, I would rather believe that there is a God and then find out there isn't, than not believe in God and then find out there is.