The following has been produced by AI.
ἀφίστημι (aphistēmi) is a compound verb formed from ἀπό (from, away from) + ἵστημι (to stand, to set).
Present Active Infinitive: ἀφιστάναι
Future Active Indicative: ἀποστήσω
Aorist Active: ἀπέστην
Perfect Active: ἀφέστηκα
Intransitive (aorist, perfect, future tenses):
to withdraw from
to depart from
to fall away from
to keep away from
Transitive (present, imperfect, future tenses):
to cause to withdraw
to remove
to lead away
Physical departure:
Luke 2:37 - Anna "never departed (ἀφίστατο - imperfect) from the temple"
Luke 4:13 - Satan "departed (ἀπέστη - aorist) from him until an opportune time"
Acts 12:10 - The angel "departed (ἀπέστη - aorist) from him"
Spiritual apostasy/falling away:
Luke 8:13 - "in time of testing fall away (ἀφίστανται - present)"
1 Timothy 4:1 - "some will depart (ἀποστήσονται - future) from the faith"
Hebrews 3:12 - "turning away (ἀποστῆναι - aorist infinitive) from the living God"
Withdrawal or separation:
Acts 5:38 - "Keep away (ἀπόστητε - aorist imperative) from these men"
Acts 15:38 - "had withdrawn (ἀποστάντα - aorist participle) from them in Pamphylia"
2 Corinthians 12:8 - "to depart (ἀποστῇ - aorist subjunctive) from me"
The word appears in classical Greek literature with similar meanings of physical separation or withdrawal. In the Septuagint (LXX), it often translates Hebrew words related to turning away from God (סור - sur) or rebellion (מרד - marad).
The word carries particular weight in passages dealing with apostasy or falling away from the faith. Its use in 1 Timothy 4:1 and Hebrews 3:12 is especially significant in discussions about perseverance and apostasy. The physical meaning of "standing away from" develops into the metaphorical sense of abandoning a previous commitment or belief.
ἀφίστημι (aphistēmi) is indeed used in both Acts 21:21 and 2 Thessalonians 2:3. Let me analyse these contexts and add other related uses:
Acts 21:21
"κατηχήθησαν δὲ περὶ σοῦ ὅτι ἀποστασίαν διδάσκεις ἀπὸ Μωϋσέως"
Here, interestingly, we see the noun form ἀποστασίαν (apostasian) rather than the verb ἀφίστημι, but it's from the same root. The accusation against Paul was that he was teaching Jews to "forsake" or "depart from" Moses' teachings.
2 Thessalonians 2:3
"ὅτι ἐὰν μὴ ἔλθῃ ἡ ἀποστασία πρῶτον"
Again, we see the noun form ἀποστασία (apostasia). In this eschatological context, it refers to "the rebellion" or "the falling away" that must precede the Day of the Lord.
Other significant uses:
Acts 5:37
"ἀπέστησεν λαὸν ὀπίσω αὐτοῦ"
Here the verb is used of Judas the Galilean who "drew away" people after him in revolt.
1 Timothy 4:1
"ἀποστήσονται τινες τῆς πίστεως"
The verb form is used to describe those who will "depart from the faith."
Hebrews 3:12
"ἐν τῷ ἀποστῆναι ἀπὸ θεοῦ ζῶντος"
The infinitive form describing "departing from the living God."
In Acts 21:21, the noun form refers to religious apostasy specifically from Mosaic law
In 2 Thessalonians 2:3, the noun describes a significant eschatological event of rebellion/apostasy
The word family (both verb and noun forms) consistently carries the idea of:
Deliberate separation
Movement away from a previously held position
Can be physical, political, or spiritual departure
The theological weight of these uses, especially in 2 Thessalonians 2:3, is significant as it describes a specific future event of rebellion or apostasy that will precede the Day of the Lord. This is not just individual apostasy but appears to be a broader movement of rebellion against God.