Jack Kornfield wrote, "The near enemies are qualities that arise in the mind and masquerade as genuine spiritual realization, when in fact they are only an imitation, serving to separate us from true feeling rather than connecting us to it." So, for example, pity is the near enemy of compassion; indifference is the near enemy of equanimity. I think intellectualism is the near enemy of wisdom.
It is really hard sometimes to judge for ourselves whether we're really maturing spiritually or just kidding ourselves. This is one reason that it's good to check in with a teacher at least now and then, because a skillful teacher will point out your self-deceptions. Otherwise ego is our "teacher," and ego makes a terrible teacher.
Practice is a process of clarification, and mostly we are clarifying ourselves. As we clarify, we are closer to true feeling. We learn to stop trying to be the star of our own inner play. We also learn to be patient and compassionate with ourselves.
Sometimes we may feel we're "done." We recognize our past self-deceptions, but we think we've got most of them rooted out. That's another self-deception. The clarification process never ends.
Teachers tell us that realization doesn't mean our illusions disappear. Instead, realization is recognizing our illusions as illusions. This begins by letting practice bring us home to ourselves. Along the way we all get fooled by near enemies sometimes. And then we recognize the fooling, and let it go, and go on. That's our practice.
Near enemies are not necessarily "bad," as long as we don't cling to them for very long. They can teach us a lot about ourselves. However, sometimes people fall in love with a near enemy and can't let it go, and that's a massive hindrance. So watch out for that.