For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms" (Ephesians 6:12) means that the true battle Christians face is not against physical people, but against unseen spiritual forces of evil like demons and Satan, who operate in the unseen realm and seek to influence people's lives negatively.

The Geneva Bible 1560 

 Ephesians 6:11 says, "Put on the whole armor of God, that you may be able to stand against the wiles of the devil

The theme of Ephesians 6:10-11 is "Dressed and Ready for Battle!". The verse compares a believer's spiritual battle to a Roman soldier entering battle without a full suit of armor or all of their weapons. The verse suggests that believers must use every part of God's armor to be successful in spiritual battle.

The Geneva Bible is a Protestant (Reformed) Bible based on the Tyndale Bible, the Textus Receptus, and the Masoretic Text