For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms.
GNT – This famous verse describes the spiritual battle that exists in the lives of believers. It does so perhaps better than any other words in Scripture. First, Paul affirms our battle is indeed spiritual, not physical. The enemies we face, ultimately, are not people or objects. The Devil may use those as part of his attack, but our true opponent is not other people: it is sin.
Second, Paul identifies our spiritual enemies. This list is commonly interpreted as a vague listing of the “ranks” within the demonic armies. “Rulers” seem to indicate a top level of evil spiritual forces. “Authorities” refer to general forces of evil attacking believers. “Cosmic powers” seems to refer to the worldwide nature of this spiritual battle. “Evil in the heavenly places” again emphasises a battle beyond this world.
Spiritual battles can occur at all levels, anywhere across this world and beyond. The believer must be prepared for all types of attacks through putting on God’s armour, as Paul describes.