In the Parable of the Dishonest Manager (Luke 16:1-13), what is the central lesson Jesus intends to convey about the use of 'worldly wealth' (or 'unrighteous mammon')?

A That dishonesty is sometimes necessary to survive in a corrupt world. B That Christians should avoid any involvement in business or finance. C That cleverness and resourcefulness are virtues, regardless of ethical considerations. D That worldly resources should be used wisely to gain eternal rewards and benefit others.