Sharks are beautiful animals, and if you're lucky enough to see lots of them, that means that you're in a healthy ocean. You should be afraid if you are in the ocean and don't see sharks.
This is the reality about humanity. We are each born with an evil, God-hating heart. Genesis 8: 21 says that every inclination of man's heart is evil from childhood, and Jesus' words in Luke 11: 13 assume that we know we are evil.