Ephesians 6:10-13
10 Finally, my brethren, be strong in the Lord and in the power of His might. 11 Put on the whole armour of God, that you may be able to stand against the wiles of the devil. 12 For we do not wrestle against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this age, against spiritual hosts of wickedness in the heavenly places. 13 Therefore take up the whole armour of God, that you may be able to withstand in the evil day, and having done all, to stand.
2 Corinthians 10:3-5
3 For though we walk in the flesh, we do not war according to the flesh. 4 For the weapons of our warfare are not carnal but mighty in God for pulling down strongholds, 5 casting down arguments and every high thing that exalts itself against the knowledge of God, bringing every thought into captivity to the obedience of Christ, 6 and being ready to punish all disobedience when your obedience is fulfilled.
The Christian journey is a journey of faith and adventure, which includes spiritual warfare. Spiritual warfare is the Christian concept of fighting against the evil forces in spiritual places, pulling down strongholds and occupying till Jesus returns.
The Christian therefore must learn to always have their armour on as a good soldier and remember that Jesus is our commanding officer, and we fight according to His rules.
Our battle is not against people, please note. There are times it feels as though the people around us are the enemies. The truth is that our battle is not against flesh and blood but against unseen powers and principalities that operate through the human flesh. These powers cannot operate on their own but look for bodies to operate through.