Here's another passage with dramatic imagery, Isaiah's vision of the heavenly throneroom. Sure, it's easy for us to get distracted by the six winged seraphs (more like flying snakes than angels) but these are far less shocking for Isaiah's ancient audience. The seraphs are prepared for divine audience: they can cover their faces (for no one is meant to see God); they can cover their feet (possibly a euphemism for genitals, either way it's a symbol of purity); and they still have a set of wings to get their jobs done. But not all tasks can be assigned to heavenly servants - some require the human touch.
Still, Isaiah doesn't feel fit to be in the presence of God, let alone respond to God's call. The reluctant prophet is a stereotype in the Hebrew tradition. Though he doesn't ask for it, he is cleansed by the seraph according to the temple rites of forgiveness. Why don't we hear about burnt and blistered lips? Perhaps God's magic coals come with miraculous healing powers or maybe the story just isn't meant to be locked into such a literal framework.
Isaiah's call reminds us that a human response is often necessary to shape the world towards God's intent. Do we need to be perfect to be a part of this? No, we are made ready before we even ask. All it takes is the will to action.