Christian Theology in Plain Language, p. 208
In one of his books, A. M. Hunter, the New Testament scholar, Source unknown relates the story of a dying man who asked his Christian doctor to tell him something about the place to which he was going. As the doctor fumbled for a reply, he heard a scratching at the door, and he had his answer.
"Do you hear that?" he asked his patient. "It's my dog. I left him downstairs, but he has grown impatient, and has come up and hears my voice. He has no notion what is inside this door, but he knows that I am here. Isn't it the same with you? You don't know what lies beyond the Door, but you know that your Master is there."