Who is Jack Helms from Return from Tomorrow and what is their importance?

Jack Helms is a sergeant from El Dorado, Arkansas. He is both injured and cared for by George. George makes mention that Jack reminds him of someone, but it's some time before he realizes that it's Jesus, shining out through Jack's eyes, that's familiar. Jack tells George that he will make a good doctor and that no one can - or will - keep him out of medical school.