How Should Christians Use the Old Testament for Ethical Guidance?

The Mosaic covenant, which began at Exodus 20, was terminated when Christ died. Christians are no longer directly subject to the laws of the Mosaic covenant, but now live instead under the provisions of the new covenant. However, the Old Testament is still a valuable source of ethical wisdom when understood in accordance with the ways in which the New Testament authors use the Old Testament for ethical teaching, and in light of the specific changes brought about by the new covenant.