God wants us to trust Him completely and totally–and when we doubt, we aren't trusting Him as we should. The Bible warns that the person who constantly doubts God and fails to trust Him "is a double-minded man, unstable in all he does" (James 1:8).
At the same time, God understands our doubts, and the most important thing I can tell you is that He wants to take them away and increase our faith. Do you remember Thomas, who was one of Jesus' closest disciples? When others told him that Jesus had been raised from the dead after His crucifixion, Thomas refused to believe it. He declared, "Unless I see the nail marks in his hands and put my finger where the nails were, and put my hand into his side, I will not believe it" (John 20:25).
How did Jesus respond? He didn't rebuke Thomas or tell him just to have more faith. Instead, Jesus came to him and showed him that He was alive. The response was immediate: "Thomas said to him, 'My Lord and my God!'" (John 20:28). Tradition says Thomas became an evangelist and preached the Gospel as far as India.
When doubts come, don't let them take root in your soul. Instead, turn them over to Christ. Most of all, saturate your heart and mind every day with the truths of God's Word, the Bible. Satan will try to turn you away, but in Christ "We have this hope as an anchor for the soul, firm and secure" (Hebrews 6:19).