It's a brilliant reply to an avowed atheist.
Francis doesn't begin by refuting the atheist, he begins by thanking the atheist for being willing to even discuss it. He follows by giving a personal witness of why the Faith matters to him.
He then moves the conversation from a discussion of the points the atheist is concerned with to the central problem: Who is Jesus?
Only after he deals with this central question does he move to deal with the questions the atheist raises. The heart of the answer he gives the atheist lies in this section: