He knows if he can get you to doubt God, then maybe you will give up and abandon God's will for your life. Feelings of fear often precede feelings of doubt and uncertainty. If left unattended, these runaway emotions can cause you to stop trusting God and His ability to provide for you. One of the best sources in combating fear and doubt is the reading of God's Word. Committing yourself to a daily reading program will show you many ways to handle doubt without feeling that you have let God down in some way.
Prayer is essential in fighting fear, doubt, and any number of other emotional problems.
In essence, prayer is faith in action. When we pray, regardless of whether we feel like it or not, we make a statement of faith. We pray because we see God as a solution to what we are facing. The book of Psalms is a great source of encouragement. They reveal personal conquest over emotions such as fear, doubt, loneliness, and discouragement.