When we as believers experience struggle, to the eye this struggle will appear to be a struggle against people of flesh and blood. But Scripture says that we do not have a struggle against flesh and blood, but that behind what we see, other powers are hidden:
Ephesians 6
12 For our struggle is not against flesh and blood, but against the principalities, against the powers, against the rulers of the darkness of this age, against the spiritual forces of evil in the heavenly realms.
We have been seated together with Christ in heaven (Eph. 2:6) and there is our life (Col. 3:3). Earlier in the Epistle to the Ephesians, Paul therefore said:
Ephesians 3:10 so that now through the ecclesia (>congregation) the manifold wisdom of God might be made known to the principalities and the powers in heaven. God now makes known His multicolored wisdom to the principalities and powers in heaven through His ecclesia (=the called ones). Those powers are the spiritual forces that control this world. Behind the scenes, for they are spiritual powers and therefore invisible. We are their opponents, because we have been placed with Christ over the universe (Eph. 1:22).
victory
The battle we experience is therefore indeed not against flesh and blood, for behind the visible battle lie these invisible powers. We need not worry either, for in Christ we are more than conquerors (Rom. 8:37). The outcome is already determined; He has achieved the victory, and we will be placed with Him over the universe.
When Paul speaks of the spiritual battle, he calls for putting on the spiritual armor. Not to fight actively, but to stand firm. Our battle is not to engage in the battle, but that we are fought against and remain standing in that battle. Four times in Ephesians 6, Paul uses the word stand or stand then! For we stand in His victory. Success guaranteed!
spiritual “weapons”
Do we experience struggle as believers? At its core, that is not a struggle against flesh and blood. Even if we undergo it in societal, earthly relationships, for that is what Paul spoke of in Ephesians 5:22 through 6:9. As an employee, in the family, or even in marriage? It is not a struggle against flesh and blood. The “weapons” we would employ are therefore neither material nor carnal:
Ephesians 6
14 Stand therefore, having girded your loins in truth, having put on the breastplate of righteousness,
15 and having your feet shod with the readiness of the gospel of peace.
16 In everything taking up the shield of faith, with which you will be able to extinguish all the fiery darts of the evil one.
17 And receive the helmet of salvation and the sword of the Spirit, which is the word of God.