The Absense of Doubt
Many beliefs we hold are not from research and careful thought. We could all probably use a little more intellectual honesty with ourselves, and it starts with the right attitude. Avoid the god complex, consider in good faith all possibilities (including those you disagree with on the outset), spend time researching before concluding, study your own viewpoint as much as those that differ from yours (you'll learn something regardless). Socrates had it right: start with knowing that you know nothing.