You are talking about "proof," which is not what science is about. In science, nothing is ever proven. One "proves things" in court.
Mark is challenging Matt to at least consider spiritual possibilities-in part because hMatt's done such a good job in raising up some interesting issues while refusing to consider Spiritual possibilities.
Susan, Matt's a real atheist, not the evangelical kind, and he's studied what he reports about.
He asks good questions.
He's someone you could learn from.