The Calvinist's idea of an actual as opposed to an imagined point of contact is not just some useless notion. It is the only intelligible point of contact possible. The non-Christian holds that pure chance and absolute fate are equally ultimate and mutually correlative limiting concepts or heuristic principles which man uses to explain the fact that we have learned much about the world, that there is order in the world, a uniformity, while there is also continual change and development. But the non-Christian's "explanation" is no explanation at all. To say "it just happens" as an explanation of an event is really to say, "There is no explanation that I know of."
I want to bring to the reader's attention and suggest the (re-)reading of Van Til's "My Credo". It's a great read for those who have never done so and a delightful reunion for those who have previously known it.