Over the last few months, I've acquired quite a few "friends" on Facebook. I noticed one of my "friends" had posted how confused he was about the Bible--in particular, how God populated the earth through Adam and Eve. He also questioned whether or not Ezekiel saw aliens in one of his visions (chapters 1-10) and so forth. Just reading his status updates, I could tell he had quite a bit of doubt about the Bible. Doubt is one of Satan's tools in spiritual warfare.
The devil likes for us to question God's Word and whether or not it is true. After all, it was written by imperfect humans. Have you ever noticed how some people can read a verse and have a different interpretation of it than you? It's usually an interpretation that allows them to believe what they want so they can live the way they want to live. It's usually a way that holds the least amount of work, effort, pain and discomfort! If you find yourself having to manipulate a very clear cut commandment of God in order to justify your own opinion, you are on a slippery slope.
Satan also likes to get us to question our relationship with God. The devil used the same tactic on Jesus. After Jesus was baptized, the heavens were opened and God said in Luke 3:21-22, "You are My beloved Son, in You I am well pleased." Jesus went into the wilderness for prayer and fasting and the devil followed him with questions hoping to get him to doubt who he was. Why? Because if the devil could get Jesus to question who He was, he might get Jesus to question everything else He believed and was called to do. The devil tried it with me when I found myself up against a lawsuit and was barred from working in the television media which I shared in my book, "Forecasts and Faith: 5 Keys To Weathering The Storms of Life."
Satan will also cause you to doubt your Christian walk. He tries to get you to doubt the importance of going to church, reading and studying the Bible, prayer, praise, tithing, witnessing to others and using your spiritual gifts to bless others. Why would he target these things? Because he knows if he can get you to fail in one are of your Christian life, you will be a weak witness for Christ. You won't have joy and inner peace. You won't rely on your faith in God in the hard times. When you do that, you become less effective for Christ and the devil has you right where he wants you! If he can't keep you from being saved, he'll at least try to keep you from being a persuasive witness.
So you see, doubt is aimed at pulling you away from God, keeping you from fulfilling your purpose, and destroying your witness for Jesus.