"And as [Paul] was saying these things in his defense (ἀπολογέομαι) Festus said with a loud voice, 'You’re out of your mind (μαίνομαι), Paul. Your great learning/knowledge (γράμμα) is driving you out of your mind (μανία).' But Paul said, 'I am not out of my mind, most excellent Festus, but I am speaking true and rational words (ἀληθείας καὶ σωφροσύνης ῥήματα ἀποφθέγγομαι).'" - Acts 26:24-25
As Paul finishes his legal defense before King Agrippa and Governor Festus, Festus has had enough. He suggests Paul is a crazy man. But Paul dismisses that notion immediately. The account he has just given of his conversion and call is factual and real, though it doesn't fit into Festus's worldview paradigm. Paul knows he is speaking true and rational words.
As Christians, we can be confident our faith is true and rational. The biblical worldview fits reality like no other worldview. Some of our assertions--the garden of Eden, the flooding of the earth in Noah's day, Israel's crossing of the Red Sea, the miracles and resurrection of Jesus--sound incredible to modern man, as they did to ancient man. But facts are facts, and they demand an explanation. When we believe the Bible and communicate its truths, we are communicating what is true and rational. Our faith is not an irrational one, and it doesn't lead to madness.
Father, give us confidence. In believing your word we have nothing to be ashamed of. Your word always proves true in the end. Thank you for special revelation--what you have revealed to us through your prophets and apostles. You have not left us in a world of postmodern, existential doubt. You are there, and you are not silent. Give us true beliefs, and make us to be bold in what we say as Christians. In Jesus' name, amen.