1 John 5:4 For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith.
Our enemy hates faith:
The devil hates the faith that we place in God and so he attempted to destroy Job because Job put his faith in God (Job 9). When his first attempt failed he tried another route to destroy Job’s faith in God. The devil is not omniscient so he cannot know our faith as God knows it, and the only way he can see it is by our faith and works together (Jam 2:17-20). The devil rejoices in the many who claim to have faith (be saved) and do not express it in works and actions.
The enemy attacks believers:
The enemy is an expert at getting us to give up, weaken or leave the faith. When Peter walked on the water he took his eyes off Jesus and immediately sank in the water. When a man’s son was possessed of a demon he asked Jesus for help and expressed his need of increased faith (Mk 9:24); the disciples also asked for their faith to be increased (Lu 17:5). The enemy will cause many things to happen or simply get us to sin and then we blame God. Paul urges us to take the shield of faith to quench all the fiery darts of the devil – fiery carries the idea of burning with anger, lust or fear and darts are daggers or small spears. The enemy will jab us with them in times of difficulty and trouble and try to get us to give up our trust in God. When anyone comes to faith in Christ the enemy loses a follower but he is not easily discouraged – he will continue to work upon the convert to keep them from continuing in the faith.
One of the ways that the devil will try to weaken or divert our faith is to cause us to start to think on emotion levels instead of trust in God. There are many times that we do not feel saved or feel the presence of God with us and he tries to get us to abandon our faith.
The devil is defeated through faith:
John tells us that we win through our faith (1 Jn 5:4); Jesus said that if we had the faith as the grain of mustard seed we could do mighty deeds (Matt 17:20). Even though the particular demon that Jesus cast out He was not saying the disciples would not be able to cast out, but they were instructed to build their life up in faith and follow the proper means to be mighty in deed. (Matt 17:21). We must always remember that it is not faith that defeats the devil, but Christ and the battle is enjoined through faith and trust in Him as His disciples.