BAPTISM OF BLOOD. Martyrdom in the case of a person who died for the Christian faith before he or she could receive the sacrament. The effects of martyrdom of blood are the complete remission of all sin and the title to immediate entrance into heaven. The expression entered the Christian vocabulary during the first three centuries when many catechumens awaiting baptism and pagans suddenly converted to the Christian faith were martyred before they could receive formal baptism of water.