What is Ephesians chapter 6 verse 12 in the bible talking about?

For we do not wrestle against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this age, against the spiritual forces of evil in heavenly places. — Ephesians 6:12

In most of Chapter 6, Paul is reminding the church at Ephesus to be spiritually-strong. He is reminding them that their defensive armor, as well as their offensive weapons, are both spiritual. He is reminding them that their true enemy is a spiritual enemy. Of course, Christians then and now do have enemies (in the world) but here Paul is reminding them of their greater enemy (not of this world). This enemy is Satan and everything within his kingdom. This kingdom uses many forces (including in and through people and organizations) with the intent to steal, kill, and destroy.

Note, I’m a Deliverance minister. I’ve battled spiritual evil. While many of other answers to this question come from academicians who have theory or rhetoric or non-spiritual justifications for what Paul means I will be answering this question as someone who actually believes in the Bible, in Spiritual Reality, in real Spiritual Enemies, and the reality that Christians are called into Spiritual Warfare. This is clearly what the text says and clearly what Paul meant. This part is certain and non-negotiable.

Entire books have been written in detail to describe the Satanic kingdom and the operations of spiritual evil. I’m going to provide a super-short answer just to steer you in the right direction. Keep in mind different deliverance ministries have slightly different theories and understandings of howexactly things should be labeled and organized. However, the general idea has a consensus and they all have 90%+ in common. The exactness of the labeling isn’t that important. It’s our attempt to examine our enemy and know him better so we can war against him more effectively. What is most important is knowing WHO the enemy is, HOW they attack Christians, and HOW to defend yourself. Paul gives you this in Scripture. If you’d like to know which books I would recommend let me know.

The general structure works like this:

1. KINGDOMS — Jurisdictions of evil with specific purpose/intent. Within specific kingdoms exist the following:
2. PRINCIPALITIES — Chief of order, time, place or rank (the demonic brains behind evil strategies)
3. POWERS — Those demons who exert the authority or right delegated. High-ranking, evil supernatural powers, as well as the power of sin and evil in operation in the world.
4. MINIONS/ASSIGNMENTS — Lower ranking demons assigned to specific tasks.
5. RULERS OF THE DARKNESS — This might include any of the above high-ranking officials who might be considered a “ruler,” or even things like the various forms of Occultism or Witchcraft or Divination. These practices derive their power from the previous demonic kingdoms and sources, and thus are knowingly or unknowingly victims and slaves to their evil agenda. Nonetheless, the human practitioner still “rules” the darkness in this age by giving these non-physical, spiritual entities access to our physical world in ways that permit them to do more damage in it.
6. SPIRITUAL FORCES OF EVIL IN HEAVENLY PLACES — Might as well say “…in spiritual places.” It’s the same thing. By “heavenly” Paul is referring to the spiritual dimension of our existence on Earth, not actual Heaven, as in where God and the angels are. None of this evil is in Heaven. It is all on Earth, in the spiritual realm, cast out of Heaven during the fall with Lucifer. Essentially, Paul is wrapping all of this (Satan, other fallen angels, demons, witchcraft powers, etc.) in it’s various forms into one category — spiritual evil that influences life on Earth. All that which opposes the Holy Spirit’s work.

I hope that helps and may God bless, strengthen, and protect YOU who are reading this..