Ephesians 6:12
Ephesians 6:1212For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this world’s darkness, and against the spiritual forces of evil in the heavenly realms.
— "our struggle is not against flesh and blood, but against the governments, against the authorities, against the world rulers of this darkness, against the wicked spirit forces in the heavenly places" — is accepted in JW teaching as describing spiritual warfare against Satan and his demonic system. The "world rulers of this darkness" are often interpreted as the political-governmental system Satan uses to oppose Jehovah's organisation.
is doctrinally important for what it says about "flesh and blood" as a Semitic idiom. Paul uses the phrase here to mean "ordinary human beings" in contrast to "wicked spirit forces." This matches — "flesh and blood cannot inherit the Kingdom of God" — where "flesh and blood" means mortal human weakness, not "physical substance." Jesus uses the same idiom in : "flesh and blood has not revealed this to you, but my Father in heaven." Paul uses it again in : "I did not confer with flesh and blood." In every instance the idiom means mortal humans, not physical matter. This matters because the Watchtower uses to argue for a non-bodily resurrection and a non-bodily return of Christ. , , and settle what "flesh and blood" actually means — and once the idiom is recognised, the objection to bodily resurrection collapses. The risen Christ himself tells the disciples in , "a spirit does not have flesh and bones, as you see I have" — deliberately choosing "flesh and bones" over "flesh and blood" to make the same point Paul makes.