apostasia denotes a departure, described as turning from Moses’ customs and as an event that must come first before a day arrives.

The two occurrences portray a departure: in Acts 21:21 it is taught away from Moses and customary practice, while in 2 Thessalonians 2:3 it is an event said to come before the day under discussion.

1. Departure from an established practice or commitment · dominant

   In Acts 21:21, the accusative singular form occurs in the charge that someone teaches a departure from Moses, followed by not circumcising and not walking according to the customs; the APB renders the clause “you teach apostasy from Moses.” In 2 Thessalonians 2:3, the nominative singular form is the event that must come first before the day mentioned; the APB renders “unless the apostasy comes first.”

   Acts 21:212 Thessalonians 2:3

In the Anselm Project Bible: The APB uses “apostasy” in both verses, presenting it once in a teaching away from Moses and once as something that “comes first.” These renderings confirm the clauses’ overall presentation rather than isolate every nuance of the term.