Quote from Greg Bahnsen in his closing remarks in a debate with Dr. Gordon Stein (Stein representing the atheist position).
Audio and printed transcript available here.
The full context of the quote below:
Moderator: Dr. Stein, the final question is directed to you. It reads:
You have said that there has been no adequate evidence put forth for God’s existence. What for you personally would constitute adequate evidence for God’s existence?
Stein: Well, it’s very simple. I can give you two examples. If that podium suddenly rose into the air five feet, stayed there for a minute and then dropped right down again, I would say that is evidence of a supernatural because it would violate everything we knew about the laws of physics and chemistry.