Why we cannot test for God
This statement is presumed and assumed by many. But it is deeply flawed.
Why? Because it assumes something about God that Christianity and Judaism deny. That God is not personal. If God is personal (ie he interacts with humanity not as a force but as a being that responds and answers based on our behavior), than we have to ask: is God is the sort of God that allows himself to be tested?
When science tests humans, they often take steps to prevent the humans from knowing they are being tested (with blind tests or lying to them about the nature of the test). But if there was an all knowing God, he certainly could not be tricked. So who says he would allow himself to be tested.
When the Russians made the first orbit of earth, the astronaut, Yuri Gagarin, wryly declared "I have been to heaven and God is not there." To this, CS Lewis responded that God does not relate to man the way an upstairs neighbor relates to a downstairs neighbor, he wrote,
"If there is a God who created the world and created us, I could no more “meet” Him, than Hamlet could meet Shakespeare. If Hamlet wants to prove there is a Shakespeare, he’s not going to be able to do it in a lab, nor is he going to be able to find Shakespeare by going up into the top of the stage. The only way he will know something about Shakespeare is if Shakespeare writes something about himself into the play."We relate to God like a character relates to the author of a novel. We know him if and only if he writes himself into the story. We know him because he is evident in the text of the story. Every tree. Every breath. Every smile. Every song. Every laugh. Every flower. Every peace of bread and cup of wine is a pointer to the author. We know him because he reveals himself to us. We don't put him in a test tube.