Paul stated that our enemies are not flesh and blood but spiritual beings who are used by Satan to bring chaos and confusion to the churches of Jesus Christ.
12 For our struggle is not against flesh and blood, but against the rulers, against the powers, against the world forces of this darkness, against the spiritual forces of wickedness in the heavenly places—(Eph 6:12).
The Greek word struggle that he used in verse 12 was actually a military term and it referred to where opposing armies would directly meet on the battlefield. It was the most dangerous place on the battlefield and usually a place of carnage. Using that word struggle emphasized to the Ephesian Christians how serious their spiritual opposition is. The way the cohort protected itself at that most dangerous place in the battle was to be superbly unified. In the same way, Christians have to be unified in truth, faith, the hope of salvation, the gospel, and prayer.