Christian vegetarianism is the practice of keeping to a vegetarian lifestyle for reasons connected to or derived from the Christian faith. The three primary reasons are spiritual, nutritional, and ethical. The ethical reasons may include a concern for God's creation, a concern for animal rights and welfare, or both. Likewise, Christian veganism is not using any animal products for reasons connected to or derived from the Christian faith. Pescatarianism was widespread in the early Church, among both the clergy and laity. Among the early Judeo-Christian Gnostics the Ebionites held that John the Baptist, James the Just and Jesus were vegetarians.

Christian ethics, also known as moral theology, is a multi-faceted ethical system. It is a virtue ethic, which focuses on building moral character, and a deontological ethic which emphasizes duty. It also incorporates natural law ethics, which is built on the belief that it is the very nature of humans – created in the image of God and capable of morality, cooperation, rationality, discernment and so on – that informs how life should be lived, and that awareness of sin does not require special revelation. Other aspects of Christian ethics, represented by movements such as the social Gospel and liberation theology, may be combined into a fourth area sometimes called prophetic ethics.