The Greek adjective αὐτάρκης
occurs in Philippians 4:11, its only appearance in the GNT. NWT 2013
still renders the adjective with "self-sufficient" while grammarian and scholar William
Mounce offers the rendering, "for I have learned to be content." Either translation is acceptable.
On the other hand, in 1 Timothy 6:6 and 2 Corinthians 9:8, Paul uses the Greek noun αὐτάρκεια. This noun is a cognate of the adjective αὐτάρκης, so they are related words. Here are some translations that I found for αὐτάρκεια:
So either "contentment" or "self-sufficiency" are fine renderings for αὐτάρκεια. Nevertheless, to show the difference between Paul and the Stoics, please consider these points: "self-sufficiency" is contextual: the Stoic view of being autarkic is
not the Pauline view. The inspired apostle said that he learned to be
self-sufficient regardless of what he possessed, whether he had much or
little. Note how he goes from describing self-sufficiency/contentment to identifying the source of his ability to be self-sufficient (Philippians 4:13). Compare
also 1 Timothy 6:6-8. - sufficiency
- contentment
- self-sufficiency
- independence
See https://ourarchive.otago.ac.nz/bitstream/handle/10523/5576/ThorntonDillonT2015PhD.pdf?sequence=1