Scientists have scanned the living brains of 20 devout Christians praying to God, and found that these brains showed activity in areas used when talking to living people, as opposed to Santa Claus.
Both atheists and Christians are happy with the results - the Christians because it is now proven that God is real, and the atheists because it is now proven that Christians really are insane.
(I assume my brain would light up in really strange places if observerd during prayer, since I believe God is superpersonal - being a person is our volume but God's surface, so to speak. Or in ether worlds, I am the fictional character who would cease to have substance if God stopped believing in me. It makes for some weird interactions, I guess. I would also almost certainly be disqualified from an experiment requiring "devout Christians".)