8 Be alert and of sober mind. Your enemy the devil prowls around like a roaring lion looking for someone to devour. — 1 Peter 5:8 NIV
Paul is telling us to be spiritually alert, sober minded and armed for battle. The demonic forces are well-trained in deception and guerrilla tactics. They are very good at creating illusions that deceive “even the elect”.
24 For false messiahs and false prophets will appear and perform great signs and wonders to deceive, if possible, even the elect. 25 See, I have told you ahead of time. — Matt. 24:24, 25 NIV
So, what does it mean to be spiritually alert? It means that we have to be prayed up, full of the Holy Spirit and well disciplined in our study of the Holy Scriptures. Jesus defended Himself against the devil by quoting scriptures to Him. If Jesus needed the scriptures to ward off satan then we surely need them even more. We need to be aware of where we are weak. The demons know our weaknesses and they attack us in those areas. Don’t walk too near the edge of the cliff. If certain things cause you to be excessive or respond wrongly. stay a long way away from those things. Your pride will tell you that you can handle the situation but your Spirit knows better. Let the Spirit man rise up and mortify the flesh.
12 Therefore, brothers and sisters, we have an obligation—but it is not to the flesh, to live according to it. 13 For if you live according to the flesh, you will die; but if by the Spirit you put to death the misdeeds of the body, you will live. 14 For those who are led by the Spirit of God are the children of God. — Romans 8:12-14 NIV
The battlefield is the mind, if we allow the Holy Spirit to control our thoughts, then we can win the battles.
4 The weapons we fight with are not the weapons of the world. On the contrary, they have divine power to demolish strongholds. 5 We demolish arguments and every pretension that sets itself up against the knowledge of God, and we take captive every thought to make it obedient to Christ. — 2 Cor. 10:4, 5 NIV