I believe that every saint (cp Php 1:1) is in Christ Jesus and as a result of their new position in the Kingdom of light (Ep 5:8, 1Th 5:5, cf their transfer at the time of their new birth in Col 1:13, Acts 26:16, 17, 18, esp verse 18) are involved in an invisible war with the world system opposed to God, the fallen flesh and the fallen angel, the devil and his demons, so that this supernatural struggle is "not against flesh and blood" but against a hierarchy of organized demonic forces composed of "rulers...powers...the world forces of this darkness...the spiritual forces of wickedness in the heavenly places" (Ep 6:12, cf 2Co 10:3, 4, 5), that Satan is a real enemy who was created (cp the Christ the Creator Col 1:16) a perfect angel (Ezekiel 28:13, 14, 15, 16, 17), that he desired to be God which led to his fall ( repetition of "I will" in Isaiah 14:12, 13, 14, 15, 16), that he led one third of the angelic hosts (who are commonly referred to as demons or evil spirits, cp Acts 19:12, 13) to rebel against God and be cast out of heaven (Re 12:4), that these demonic forces are organized and commanded by Satan (the devil, the serpent of old, the great dragon Re 12:9) "who deceives the whole world", that he "prowls about like a roaring lion, seeking someone to devour" (1Pe 5:8), that he is the father of lies (Jn 8:44), but that his lies ("fiery missiles" or "flaming arrows") can be extinguished by taking up the shield of faith and obeying what God says is true (Ep 6:16), that in this invisible war believers are called to humble themselves (depending on and receiving His "greater grace" Jas 4:6, cf 2Cor 12:9, 2Co 12:10), that believers are to submit to God and resist the devil who will flee (Jas 4:7), that Christ "through death" on the Cross rendered "powerless" the devil "who had the power of death" (Heb 2:14, 15), that believers also battle against the evil, godless world system (which hates Jesus and His followers Jn 15:18,19) but which has been overcome by Christ (Jn 16:33, Gal 6:14), that believers battle against "fleshly lusts (Jas 1:13,14, cp Gal 5:17), that these lusts relentlessly wage a strategic war against our souls (1Pe 2:11), but that the power of Sin (which is personified as a powerful, ruthless tyrant or slave master) and the fallen flesh have been broken by Christ's death, burial and resurrection (which equates with the "Gospel" 1Co 15:1, 1Co 15:2, 1Co 15:3, 4, 5, cf Ro 6:11, Ro 6:12, 13, Ro 6:14), so that believers can now walk as overcomers (1Jn 4:4, 5:4), as "more than conquerors through Him Who loved us" (Ro 8:37KJV) and as they walk by the Spirit of Christ, they are enabled to not fulfill the desires of the flesh (Gal 5:16 Beware, do not "invert" the order, i.e., try in your strength to "not carry out the desire of the flesh", but first continually surrender your will to the Spirit Who will empower you to overcome the lust of the flesh.) In short, believers are charged to "be strong (present imperative = Continually.) in the Lord, and in the strength of His might" (Ep 6:10) and to "put on (aorist imperative = command. Do this now! It is urgent! Don't leave the house without putting on your "battle gear" beloved!) the full armor of God" (Eph 6:11 cf Ro 13:12, Ro 13:13,13:14), that you may be able to stand firm against the schemes of the devil." (Ep 6:11), to "take up the full armor of God that you may be able to resist in the evil day" and "stand firm" (Ep 6:13), to "gird your loins with truth" (Ep 6:14 cf Mt 4:4, Jn 8:31, 32, 36), to "put on the breastplate of righteousness" (living "right" by His power) (Ep 6:14), to "shod your feet with the preparation of the Gospel of peace", to "take the helmet of salvation, and the sword of the Spirit, which is the Word of God" (Eph 6:17) and finally "with all prayer and petition pray at all times in the Spirit, and...be on the alert with all perseverance and petition for all the saints." (Ep 6:18, cf 1Th 5:17, Php 4:6, Php 4:7)