Within the parable of the Dishonest Manager (Luke 16:1-13), how does Jesus use the manager's shrewdness as a lesson for his followers?

A To endorse dishonesty as a viable strategy for personal gain. B To illustrate the necessity of accumulating wealth at all costs. C To encourage believers to be as diligent and resourceful in spiritual matters as worldly people are in material pursuits. D To demonstrate that forgiveness is always unconditional, regardless of one's actions.