Spiritual warfare is a subject that invokes mixed feelings among people. On the one hand you have those who have made it the bedrock of their entire theological system and basically operate with the belief that people sin because of the devil, while on the other hand you have those whose system of theology seems to ignore the subject of spiritual warfare all together. Both systems of thought are faulty at best and can be detrimental to one’s spiritual progress. Thankfully the Bible has quite a lot to say about Christians overcoming the schemes of the evil one. It is therefore important that believers are aware and equipped for the spiritual battle that they are engaged in. Thomas Brooks’ balanced advice to believers is on point when he says, “Christ, the scripture, your own hearts, and Satan’s devices, are the four prime things that should be first and most studied and searched. If any cast off the study of these, they cannot be safe here, or happy hereafter. It is my work as a Christian, but much more as I am a watchman, to do my best to discover the fullness of Christ, the emptiness of the creature, and the snares of the great deceiver.” 
What the Bible says
Be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour. 1 Peter 5:8
The imagery in this text is rather vivid. All you have to do is think of how the king of the jungle skillfully picks, stalks and hunts down his prey, and after he has pounced, he tears it apart ruthlessly; that dear friends is our everyday danger. No wonder Peter urges his readers to be sober and vigilant. After all Peter should know. Christ warned him of the impending attack on his life from Satan, and what exactly was the devil’s plan? To sift Peter like wheat. Hours later the over confident Peter was denying Jesus three times.
Finally, be strong in the Lord and in the strength of his might. Put on the whole armor of God that you may be able to stand against the schemes of the devil. For we do not wrestle against flesh and blood, 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. Ephesians 6:10-12
This passage reminds us that (1) spiritual warfare is a reality, (2) our enemies are real, powerful and conniving (3) believers can only overcome if they are walking in the Lord and by His grace. In other words, Christians who are not walking worthy of their calling cannot stand against the schemes of the devil. Spiritual warfare is in essence a battle for righteous and godly living. Invariably those who are striving to live godly lives become targets of concerted spiritual attack.
Possible signs of spiritual attack
Since the devil’s schemes are intended to hinder you from living a godly and righteous life, you can tell you are under attack when your relationships with God and people are not as they should be. It is the devil’s every intention to ensure that you do not walk right with God and that you have ungodly and unbiblical relationships with other people (spouse, friends, family, boy/girlfriends, workmates, etc.) Let me therefore offer four SUBJECTIVE signs of spiritual attack.
1. Increased and unusual marital and family conflict
The home is the best indicator of people’s spirituality. It is also the most vulnerable to the schemes of the devil, primarily because families make up churches and the state of the family is indicative of the church.
2. Increased or sudden discouragement, despair and discontent
Elijah is a perfect case in point. After he spectacularly defeated the wicked prophets of Baal and had experienced the Lord’s hand in a special way, he suddenly became discouraged, discontent and despaired. Nothing had really changed, the enemies were the same, the threats and dangers were the same, but suddenly the courageous Elijah was despairing and ready to throw in the towel. One could argue he was under a spiritual attack.
3. Struggles to attend to the means of grace
By that I mean struggling to read/study the Bible, to pray privately and publically, to worship, to fellowship with other believers, etc. These are the means by which we grow in godliness and Christlikeness. The devil will ensure that he distracts and discourages us from doing them.
4. Increase in sudden and/or recurring temptations
Memories of past sins or failures suddenly pop up. Or sometimes there is an unusual increase in the rate of temptations. Remember Job? He was hit suddenly from all angles.
What is one to do?
But he gives more grace. Therefore it says, “God opposes the proud but gives grace to the humble.” Submit yourselves therefore to God. Resist the devil, and he will flee from you. Draw near to God, and he will draw near to you. Cleanse your hands, you sinners, and purify your hearts, you double-minded. James 4:6-8
1. Acknowledge your weakness and struggles
You cannot submit to God and seek His grace without humbly acknowledging your weakness and struggles. Blessed are the poor in spirit (Matt 5:3).
2. Confess and repent of sin
He who conceals his sins will not prosper but he who confesses them will receive compassion. (Proverbs 28:13)
3. Attend to the means of grace even when you do not feel like it
You will not always feel like praying, reading the Word, worshipping or fellowshipping. Do it anyway. Soldier through it, and you will know God’s grace.
4. Seek accountability
That is what meaningful friendship is all about after all. We need someone to ask us the tough questions and watch out for us.
5. Preach the gospel to yourself and others
Yes believers need the gospel. Mediate on what God has done to save a sinner like you and the implications of the gospel then preach it to others. There is something about it that feeds life to your soul.