"What would you say to the doubting Christian who struggles to accept the difficult or unusual things in the Bible?"
"I believe the real issue behind many of our doubts is that we want to be god instead of allowing God to be God and submitting to Him."
We live in a culture where everybody wants to live by their own rules. But when it comes to God, He is God, and we are not.
If we believe that God is all-powerful and almighty, why can we not accept that He, in His supernatural power, accomplished impossible things? For instance, Jonah was in the belly of the whale three days; Jesus affirmed that fact (see Matthew 12:40). Even secular scientists are now beginning to accept the Flood as a reality.
I believe the real issue behind many of our doubts is that we want to be god instead of allowing God to be God and submitting to Him. So I invite you to do that. Say, "Holy Spirit of God, illumine my heart and my mind so that I can trust in Your Word that you are a mighty God, that you are all-powerful God, and nothing is impossible for you."