Ephesians 6:12 For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places.
The ‘high places’ epouranios – ‘heavenly’ is not speaking of God’s heaven. It is referring the political heavens – the rulers of this world. These were the people who used their power to beat and imprison and kill those who preached the gospel.
The disciples wrestled not against flesh and blood in that they did not engage in physical fighting. They were instructed to be as harmless as doves and to love their enemies. Their warfare in preaching the gospel was to change the way that the people thought.
It was ‘spiritual’ warfare in that it was a battle for minds. The victory didn’t come until the fourth century AD when Christianity became the State religion of the Roman empire and pagan idolatry was outlawed. In winning this victory, the Church itself was compromised.
I hope you find this helpful.