This essay argues that the attempts of John Kloppenborg and several others to explain Paul's neologism θεοδιδακτος in 1 Thess 4.9 are unsuccessful. An alternative explanation is offered by taking into consideration available evidence regarding compound neologisms in Koine Greek and by drawing upon Emmanuel Tov's work on LXX translation tendencies. It is suggested that Paul draws upon Isa 54.13 in forming his neologism in a manner analogous to the ‘reverse and combine’ pattern of LXX compound-word formation noted by Tov. Paul creates a new word as part of his larger epistolary strategy of strengthening the communal identity of the troubled Thessalonian community.