The word diabolos is used in the LXX to translate Hebrew Satan, and ‘devil’ is an English alternative used in the NT (e.g. in the temptation narrative, Matt. 4: 1) as an equivalent of ‘Satan’. The belief that Satan was once an angel expelled from heaven (Rev. 12: 9) is assumed by Jesus (Luke 10: 18). But Jesus has the power to control Satan and expel the demons who are his underlings and who can take up residence in human bodies (Mark 3: 23–7).