Summary: A divine calling, whether the meaning is revealed in this life or the next, always requires our biblical heroes to do more than they feel they are capable. But all of us must answer, regardless of the call. Jonah provides a very "human" example of how difficult the work may be, and how the result might not be what we anticipate, but that it is always worthwhile and reflects God's will that we enact the purpose that brings our life to its proper fulfillment.
