Sacrifice is the offering of material possessions or the lives of animals or humans to a deity as an act of propitiation or worship. Evidence of ritual animal sacrifice has been seen at least since ancient Hebrews and Greeks, and possibly existed before that. Evidence of ritual human sacrifice can also be found back to at least pre-Columbian civilizations of Mesoamerica as well as in European civilizations. Varieties of ritual non-human sacrifices are practiced by numerous religions today.

Worship is showing regard with great respect, honor, or devotion. This may be encountered in religious settings. In such instances it may represent divine worship; reverence for a divine being or supernatural power. This activity may have other focuses, such as hero worship. Worship may involve one or more of activities such as veneration, adoration, praise, supplication, devotion, prostration, or submission. An act of worship can be performed as simple prayer or through elaborate ceremony, individually, in an informal or formal group, or by a designated leader. The focus of worship is ultimately honoring the subject in some manner.