I liked Frailty. Without giving too much away, it demonstrates how any agent with god-like powers could make you believe whatever it wants you to believe. Therefore if you ever find yourself in a universe in which gods and powerful demons exist and have an interest in influencing your life, you could fall into a situation where you have no means of determining which gods or demons are best aligned with your long-term goals. Also, a sufficiently cogent propaganda campaign could have a good chance of convincing you to commit atrocities.