The INFJ's "Sense of Rightness," about which much is written, is if anything understated. As an INFJ, I'm here to tell you, everything that is written is absolutely true.
Our intuition is so strong, so ever-present, so pervasive, that we really do rely upon it above all else. It is accurate so often that we trust it more than we trust any other input into our choices. It speaks to us from an early age, so we are very comfortable with it.
But ... here are the problems. First, "intuition" is the capacity to leap to an accurate conclusion based on fragmented, incomplete data. If the data itself is inaccurate, our "rightness" is likely to be off, no matter how powerful our intuition. And we have no mechanism for parsing this: we "feel" just as "right" when our original information is bad as we do when it is good.
Second --- we can deeply misinterpret the "Sense of Rightness," in terms of what it is. I have a close friend who's an INFJ, who has the "Sense of Rightness" and relies on it utterly ...
... and thinks it is God's voice.