Have you ever noticed that the letter Q is unnecessary? It doesn't provide any function to the language. Any word spelled with it could just as easily be spelled with other letters. Does that mean it shouldn't exist? Of course not. In this universe, everything has a place. Cosmic balance, Karma, God's plan, the laws of physics—they're all trying to describe the same thing. There is nothing that exists without purpose, and nothing without purpose that can exist. You can take solace in knowing that, just like the useless letter Q, you have birthright to exist in this world. Nothing can take that from you. 
Unless a creator God breeds technicolor angel-beasts hellbent on ripping you out of reality, of course. When Mina learns that she was a cosmic accident—a being accidentally created without purpose—what was once an easygoing life starts to entwine with conspiracies, impossible occurrences, and deadly occult mysteries. Not to mention friends so dangerous and unpredictable they make the cosmic horrors look normal by comparison. 
When the questions never stop piling up, it's hard to know where to begin. But I'll give you a hint: they all begin with a Q.