I think that Mattius has it exactly. Does God exist? Who knows. Is a belief in god rational? We could argue this till the cows come home. In the Sil is there is being who has always existed, is perfect and all powerful? Yes there is, he is called Eru. Tolkien made Eru like he made Ea.
I'm sorry? Entropy isn't really a thing, its a measure of Disorder in a closed system. It never decreases and always increases or stays the same. But it is not "created" or "destroyed" if thats what your getting at. It does not destroy energy either. Sorry do you mind explaining a bit more?