How do we understand the “heavenly places” for other than godly realms? We can find the phrase, the heavenly places, at least two times (more than two times, though) in the Bible.
The most commonly seen passage is Ephesians 6:10-12 NASB:
10 Finally, be strong in the Lord and in the strength of His might. 11 Put on the full armor of God, so that you will be able to stand firm against the schemes of the devil. 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.
The same phrase is used (for godly realms) in Ephesians 3:10 NASB:
10 so that the manifold wisdom of God might now be made known through the church to the rulers and the authorities in the heavenly places.
What is the “spiritual forces of wickedness in the heavenly places” in Ephesians 6:12? The same Ephesians explains what “spiritual forces of wickedness” is. Let’s read Ephesians 2:1-7 NASB:
2 And you were dead in your trespasses and sins, 2 in which you formerly walked according to the course of this world, according to the prince of the power of the air, of the spirit that is now working in the sons of disobedience. 3 Among them we too all formerly lived in the lusts of our flesh, indulging the desires of the flesh and of the mind, and were by nature children of wrath, even as the rest. 4 But God, being rich in mercy, because of His great love with which He loved us, 5 even when we were dead in our transgressions, made us alive together with Christ (by grace you have been saved), 6 and raised us up with Him, and seated us with Him in the heavenly places in Christ Jesus, 7 so that in the ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus.
We were all sinners who walked in the darkness inspired by the “prince of the power of the air, of the spirit that is now working in the sons of disobedience” (v.2), which is, Satan, the Devil, the Adversary who is challenging (because of a spiritual being by nature) in the heavenly places where Christ Jesus is. At this stage, the sinners and Satan are in the same level. The formally called sinners, who walked according to the principles of the “prince of the air” (because of a spiritual being by nature) in the heavenly places, are now with Christ Jesus by His work of redemption.
For this reason every saved sinner is of predestination according to Ephesians 1:3-14 NASB:
3 Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ, 4 just as He chose us in Him before the foundation of the world, that we would be holy and blameless before Him. In love 5 He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will, 6 to the praise of the glory of His grace, which He freely bestowed on us in the Beloved. 7 In Him we have redemption through His blood, the forgiveness of our trespasses, according to the riches of His grace 8 which He lavished on us. In all wisdom and insight 9 He made known to us the mystery of His will, according to His kind intention which He purposed in Him 10 with a view to an administration suitable to the fullness of the times, that is, the summing up of all things in Christ, things in the heavens and things on the earth. In Him 11 also we have obtained an inheritance, having been predestined according to His purpose who works all things after the counsel of His will, 12 to the end that we who were the first to hope in Christ would be to the praise of His glory. 13 In]Him, you also, after listening to the message of truth, the gospel of your salvation—having also believed, you were sealed in Him with the Holy Spirit of promise, 14 who is given as a pledge of our inheritance, with a view to the redemption of God’s own possession, to the praise of His glory. – T