When I say "obvious" I mean he is in plain site every day. Is it because he wants us to live our lives without knowing for sure that he exists? It would seem so, but why?
God brought Moses to Egypt to deliver the Hebrew nation. It was there that he cast a rod on the ground that turned into a snake, turned the Nile into blood, cast plague after plague on the Egyptian nation until they relented to set them free. Then God spit the Red Sea in two so they could cross and escape the wrath of the Egyptian army following them only to watch them all drown as God closed the sea on them in pursuit.
No people could be more sure of a God that exists than the Hebrew nation, so the next thing they do is lose faith by building a golden calf to worship in his stead.
Shrug.
Also look at the story of Adam and Eve who walked and talked to God in the garden, yet they lost faith and ate the forbidden apple anyway.
So as we can see, it has done God precious little in proving that he exists. No, he wants us to place our faith in him instead.