Some of those beliefs — especially the ones we have an emotional need to believe — should be questioned.
Emotions are the most powerful driving force in human nature. Getting your emotions involved in something gives you energy in the least, but which direction that energy takes you is another story.
When you have an emotional attachment to a certain belief, objectively (as much as you can) ask yourself why you need to believe so strongly. Then ask yourself if it’s possible your belief is based on your emotional need more than reality.
It’s definitely not an easy task, but a least it’s a start towards realism.