The Bible teaches that a spiritual realm lies beyond the five senses of seeing, hearing, touch, taste, and smell. Though the unseen immaterial world is significantly different from the physical one, it’s real, influential, and affects Christians daily. In addition, Jesus and others in the Bible taught about an ongoing war involving the spiritual realm, which gives many readers the desire to know more.
Spiritual warfare refers to the ongoing battle between God and Satan involving holy and fallen angels as well as people. The Bible includes important instructions to Christians so that they will be aware and successful in spiritual warfare. Jesus Christ’s death on the cross guarantees Satan’s ultimate defeat.
Why did Paul say our battle is not against flesh and blood? Who participates in spiritual warfare? Does spiritual warfare only take place in the spiritual realm? Where and why does spiritual warfare happen? Keep reading to learn the answers to these questions and others.
Also see Why Was Lucifer Cast Out of Heaven? to learn more.
Why does the Bible say our battle is not against flesh and blood?
The Gospels are clear that Jesus Christ believed in Satan and demons. He also believed in the spiritual dimension they inhabit, along with angels. Jesus interacted with the non-physical dimension when, for example, he exorcised demons from people (e.g., Mark 1:21-28). Additionally, on one occasion, Jesus explained his purpose on earth was to bind Satan so he could rescue those he held captive (cf. Matt. 12:29).
Who participates in spiritual warfare? The term “spiritual warfare” describes the battle between God, angels, and his people, against Satan and the angels who followed him in his rebellion, commonly referred to as demons. However, the Bible also mentions many other names for them (more below). Satan and his forces target believers and unbelievers, making all people vulnerable to the battle.
Does spiritual warfare only take place in the spiritual realm? Even though the word “spiritual” refers to the non-material dimension of existence, “spiritual warfare” occurs in the spiritual and physical realms. The Bible teaches that the realms influence each other. On one hand, Satan and demons can influence people to say or do certain things. On the other hand, the prayers of people can defeat their evil efforts.
One Bible teacher correctly explains: “The phrase ‘spiritual warfare’ never appears in the Bible. It’s a theological, practical term for describing the conflict of the Christian life. The spiritual battle we’re facing is an epic struggle pitted against Satan and his angels, against the principalities and powers. It is being fought every day right where we live – in our homes, our office, our marriages, our church, and in the inner core of our hearts.” 
Where did the concept of spiritual warfare originate? Some Bible scholars suggest the term “spiritual warfare” originated in the 1970s, though it’s difficult to know with certainty.  Whatever term Christians use in English (or any other language) today or in previous centuries has its roots in the wrestling and resistance language in the New Testament.
For example, Peter compares Satan to an aggressive, hungry lion seeking to pounce on and devour Christians. 1 Peter 5:8-9 read, “Be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour. Resist him, firm in your faith, knowing that the same kinds of suffering are being experienced by your brotherhood throughout the world” (cf. James 4:7).
Also see What Is a Serpent In the Bible? to learn more.
Where and why does spiritual warfare happen?
The primary front of spiritual warfare is the non-material realm, which affects the secondary front, the physical realm. In Ephesians 6:12, Paul said, “For we do not wrestle against flesh and blood [i.e., the physical realm], 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 [i.e., the spiritual realm]” (ESV).
Bible translations have different ways of describing the spiritual warfare Paul mentions. The Greek word he uses (pale) comes from the vocabulary of athletics and is related to the sport of wrestling. In fact, the Septuagint, a Greek translation of the Old Testament that predates Jesus, uses the same word to describe Jacob’s wrestling match with God (Gen. 32:24-25). 
- Like the ESV, the KJV and NKJV both read, “we do not wrestle against…” flesh and blood
- NIV and NASB read, “our struggle is not against” flesh and blood
- NLT reads, “we are not fighting against…” flesh and blood
- HCSB reads, “our battle is not against” flesh and blood
In the latter part of the verse, Paul uses four terms to describe Satan’s collective forces. The various terms imply different ranks, roles, and perhaps abilities of demons. The word “against” modifies all four descriptions, emphasizing the hostility between the parties.
|rulers||Many translations say “rulers”; the KJV and NKJV say “principalities.” The word often appears with “authorities” (e.g., Eph. 3:10; Col. 1:16, 2:10, 15).|
|authorities||Some translations say “authorities” (ESV, NIV, NLT); others say “powers” (KJV, NKJV, NASB). Like “rulers,” the word conveys rank and organization.|
|cosmic powers over this present darkness||Some say “powers” (ESV, NIV); others “rulers” (KJV, NKJV), others “forces” (NASB). Most translations say “darkness,” though the NIV says “dark world.”|
|spiritual forces of evil in the heavenly places||Some translations say spiritual “forces of evil” (ESV, NIV) or “wickedness” (KJV, NKJV, NASB). Most translations say “heavenly places,” though the KJV says “high places.”|
Spiritual warfare expert Clint Arnold explains that the terminology Paul uses for evil spirits “is suggestive of hierarchy in the demonic realm since some of these terms were commonly used to refer to various ranks of human leaders in governmental positions of authority. There does not appear to be any way for us to determine what the relative ranks and abilities of these spirits are, but it is probably not important for us to know this anyway. ” 
Also see What Is a Familiar Spirit? to learn more.
Why does spiritual warfare happen?
Since the Garden of Eden, Satan has been trying to thwart God’s plan to seek and save the lost. Satan hates God and his people. He also hates that he has ultimately lost the battle. According to Paul, the cross determined the outcome of the battle. Yet, even though Satan is a defeated power, he still tries to frustrate God’s purposes (e.g, 2 Cor. 4:4).
In Colossians 2:15, Paul writes, “[Jesus] disarmed the rulers and authorities and put them to open shame, by triumphing over them in him.”
Christian author Oswald Sander writes, “Lest we be ‘terrified by our adversaries,’ it is well to remember that Satan’s power is not inherent but permitted (Rom. 13:1). It is not unlimited, but controlled (Job 1:12; 2:6). It is not invincible, but broken (Luke 11:21-11). It is not assured of success, but is surely doomed (Rev. 20:2-3).”
Sanders continues, “Satan knows well that there is no ultimate victory for him. The pronounced sentence has only been postponed. But he works to hinder and postpone Christ’s final triumph. We can rejoice in the certainty of John’s assurance: ‘Greater is he that is in you, than he that is in the world’ (1 John 4:4).” 
Also see What Is Blasphemy Against the Spirit? to learn more.
 101 Answers to Questions about Satan, Demons, and Spiritual Warfare by Mark Hitchcock. p. 168.
 40 Questions About Angels, Demons, and Spiritual Warfare by John R. Gilhooly. p. 23.
 Ephesians by Clint Arnold. ZECNT. p. 446.
 Arnold. p. 470.
 Cultivation of Christian Character by Oswald Sanders. p. 86.
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