I am not referring to miracles. We cannot experience the ineffable. We hear a voice, we see the Red Sea parted, or we follow a fiery cloud. In the same way that we jump from sense impressions of an apple to a real belief in the being of the apple, we jump from these events to a knowledge of God. To follow this line of reasoning, we must be convinced that why questions are the right questions to be asking in the first place, but this path inevitably leads us back to questions of ultimate values and purposes.
Natural theology turns out to be a circular argument.
Here is the first good challenge to my religion. We can decide either way, and we have no way, on the face of it, to know the difference. This agnostic challenge is a good one, but it leaves the question open rather than closed. On the face of our experience, we have no reason to believe or to refuse to believe in God. I suggest that we try out both possibilities.