A child comes and knocks, on a door he does not quite yet know.

A man comes and opens it, and ask him what he seeks

A child seeks for food and shelter, a way not to perish

A man seeks to help the child, not just now but forever

A child reveals that he has a great debt, one he can never pay

A man reveals that he always knew, and that he can make it go away

A man sends his son and has him pay the price, not just for the boy, but for all of mankind.