The Greek verb aphistemi combines apo (away from) and histemi (to stand/set), meaning 'to stand away from, to depart, or to fall away.' It appears about 14 times in the New Testament in contexts ranging from physical departure to the theological catastrophe of apostasy.
The most theologically significant use of aphistemi is its role in describing apostasy — the falling away from the faith. 1 Timothy 4:1 provides a prophetic warning: 'The Spirit clearly says that in later times some will abandon (apostesontai) the faith and follow deceiving spirits and things taught by demons.' The noun form apostasia (apostasy) comes from this same root. Paul's command to Timothy captures the active dimension: 'Let everyone who confesses the name of the Lord depart (aposteto) from iniquity' (2 Timothy 2:19). Aphistemi works in both directions: one must depart from sin and not depart from Christ. Hebrews 3:12 makes the warning personal and urgent: 'See to it, brothers and sisters, that none of you has a sinful, unbelieving heart that turns away (apostenai) from the living God.' The antidote prescribed is daily encouragement, community, and holding firmly to the confession of faith (v. 13–14).