It was Hartman who defined "intrinsic" as everything what you can not see, touch or define. Definition by definning exclusion. The realm of God is there where our senses and knowledge ends. It's the realm of unknown. The more science discovers of the world, the preciser definition of God there's going to be.

God is valued systemically in theology, extrinsically in comparative religion, and intrinsically by a personal salvation. God is the supreme value, the value of values. Nothing more valuable is thinkable.

In this sense, the critical question is less whether there is absolute truth than whether and how well we can perceive it. Perhaps the only thing a human being can be truly sure of is that one can't be completely sure. That is the realm of God, even if you don't believe in God.