Nothing But The Blood is a classic Christian hymn. It was sung by Demetrius Demeter and a group of new Christian converts in a Greek holding facility for Global Community criminals and dissidents in The Mark. Albie started to sing along but was shushed by Buck Williams while they were in fear of getting caught.
Mark Eisman and the six prisoners whom Mark was executed with also sang it as they were executed. An angel visited the believing prisoners and taught them the song.