Who is the prince of the power of the air?

This description only appears in Ephesians 2:2:

Eph 2:1-2 And you were dead in the trespasses and sins 2 in which you once walked, following the course of this world, following the prince of the power of the air, the spirit that is now at work in the sons of disobedience.

So Paul equates the ‘prince of the power of the air’ with ‘the course of this world’ and ‘the spirit that is now at work in the sons of disobedience’. Paul is certainly not using the term ‘the prince of the power of the air’ to describe a supernatural devil because the air would be the last place that such a being, if it existed, would have power. It is clear from the context that Paul is using the term to describe the spirit of disobedience of people of the world who have rejected God’s way. Some of these were following their own inclinations in rejecting the way of life, but others were having power exercised over them by their rulers. We are given an example of this in John 12:42:

Many even of the authorities believed in him, but for fear of the Pharisees they did not confess it, so they would not be put out of the synagogue.

So ‘the power of the air’ is the power of the political and religious leaders, ‘the prince of the power of the air’ is sin, which motivates those leaders who turn their followers away from the way of life.

A similar description is given in Ephesians 6:12:

For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places.

Here Paul emphasizes even more strongly than he does in Ephesians 2:2 the need for the followers of Christ to resist the efforts of rulers and authorities, even their religious leaders, if those rulers are trying to force them to remain in the darkness of the world rather than walking in the light of the gospel.