"As He was setting out on a journey, a man ran up to Him and knelt before Him, and asked Him, “Good Teacher, what shall I do to inherit eternal life?” And Jesus said to him, “Why do you call Me good? No one is good except God alone.” Mark 10:17-18
This. Until a person grasps this truth the actions of the people around them (and often their own actions) will confuse and perplex. Once you realize that people are not basically good, but are actually inclined toward evil, the world will suddenly make sense.