Any true believer who greatly fears our spiritual enemy may be partly influenced by the world’s inaccurate depictions of him, or by poor Christian teaching about him. Or maybe both!
I’m a believer 44 years and I’ve never consciously feared the devil. However, it pays to be aware of how much damage he can do if we aren’t remaining steadfast in Christ each day. Anyone who fears the devil needs to get a good overview of balanced Bible teaching on the powers of darkness.
It pays to be grounded in sound teaching. It’s also very important to focus on primary Scripture teaching about him and not be distracted by less important issues, such as how and why he fell, or his future ruin, etc.
If you can, take the time to read the following. It may be a good place to start:
Our enemy takes the form of an angel of light. Sometimes he pretends or appears to be on the side of righteousness, claiming spiritual authenticity in the world and within the true Church. We need to recognise the devil's character and be wary of his activities in the world around us.
Christ “gave Himself for our sins, that He might deliver us from this present evil age” (Galatians 1:4, NKJV). We need this deliverance because “the whole world lies in the power of the evil one” (1st John 5:19, NASB), and the devil is working in those who are disobedient (Ephesians 2:2).
Those who openly oppose Truth need to “come to their senses and escape from the snare of the devil, having been held captive by him to do his will” (2nd Timothy 2:26, NASB). The god of this world works on the minds of those who do not believe to stop them seeing the truth (2nd Corinthians 4:4).
When we are wholly submitted to God as individuals and as members of a true local church, through faith in Christ's authority we can resist the devil and he will flee from us. He will be confronted by our spiritual awareness and will recognise the Person of Christ in us. We always come against him in Christ’s authority.
But we should also realise that our enemy can stand in our way, or perhaps gain an advantage. Even if we believe we are aware of his schemes, there will be times when he will hinder us: "...we wanted to come to you... and yet Satan hindered us" (1st Thessalonians 2:18).
He can cut through our intentions and thwart our plans, so we need to be set apart (pure and sanctified), fully prepared for conflict. The spiritual forces of wickedness will do their best to disrupt good works, corrupt godliness, block spiritual progress and distort true teaching. We are constantly set against an enemy who wants to frustrate the Holy Spirit's work in and through us. The more we accomplish in Christ the greater the opposition will be. Are we prepared? (Ephesians 6:10-18.)
Demonic activity can poison our attitudes and behaviour, which in turn causes "soulish" friction among true believers (consider James 3:15, 16). Paul's experience strongly suggests our spiritual enemies — working as messengers of Satan — can also cause humbling health problems (see 2nd Corinthians 12:7).
"Put on the full armor of God so that you can stand against the tactics of the Devil" (Ephesians 6:11, HCSB).