I believe this is your scruples speaking. It depends on exactly what you write, but in general no, you are not responsible for someone trying to act it out. Granted, if you write an extremely graphic sex scene that violates most taboos and then have your characters exalt over how great it was for multiple chapters, then you may be encouraging others to those actions. If you research and write out effective ways to summon demons, with all the details in the book, followed by the main character using them and proclaiming them to be great, then you may be encouraging others to follow those steps. However, a murder mystery with a great cover-up followed by a greater detective, the understanding that murder is a serious crime and the murderer is a sinful person does not encourage others to depravity. Generally a book is written that people aspire to be like the heroes and avoid becoming the villains.
Basically, if you write things that are reasonable, have the good guys eventually triumph and do not encourage evil actions with your novel, there is no worry. There will always be people with mental issues that can take things out of context and turn them into items of imitation or worship, but you cannot change that. You can simply encourage good behavior. (I wouldn’t pick up a wand and cast spells like one of my favorite characters, but he gives me courage to stand up for what is right.) You can also discourage bad behavior. Most villains in good stories have bad things happen to them, so that you can say, “got your comeuppance.” (Why murder someone who annoys me when there is always a smarter secret anget who will discover what I’ve done and, when I try to fight him, wins definitively, either by my embarrassing arrest and destruction of my personal life, or by tricking me into my own shark tank before I could kill him and his lady love.)