An offering presented to God as a token to express thanksgiving, to acknowledge guilt, and to restore good relations with him. Starting with Abel, humans offered various voluntary sacrifices, including animals, until the Mosaic Law covenant made them a requirement. Animal sacrifices were no longer needed after Jesus gave his own life as a perfect sacrifice, though Christians continue to offer spiritual sacrifices to God.​—Ge 4:4; Heb 13:15, 16; 1Jo 4:10.