It would kind of depend what you believe about the Bible, wouldn't it? After all, different people read it and draw some radically different conclusions from it, whether or not they claim to "believe" what they are reading.

It depends on how they interpret what they are reading. Some will interpret a given passage literally, while others see it as metaphor. You'll usually find that they interpret what they read in such a way that it bolsters up what they had already decided they wanted to do or believe anyway. Thus the Bible, like any other holy book, can be used by either the scrupulous or the unscrupulous to support their favorite beliefs and their general plan of action.

And so it has been. Either the forgiving or the vengeful can find some Bible passage that appears, in isolation, to be favorable to their own viewpoint.

Whether someone is "stark raving bonkers" or not is just an opinion. We're all crazy by someone else's definition, and they might be so by ours.