God is not an old man with a beard. He’s not floating around up there in space. If that’s what Christianity meant by God, then yes—science would have plenty to say. But God is not just another being out there. He’s not even the highest being. Rather, according to classical theism, God is being. The great thirteenth-century theologian Thomas Aquinas described God as ipsum esse subsistens, or the act of “to be” itself. This is beautifully confirmed in the story of the burning bush, when God reveals his name to Moses as “I am who I am” (Ex. 3:14). God just is. In God, there is no difference between what God is and that God is.