I don't think we talk about the things we really believe. We tend to take those things as givens, and just leave them alone. The things we talk about are things we are trying to sell to others and ourselves. It's that kernel of insecurity that leads us to articulate our ideas. We hope that others will buy it so that we might fully buy it, and we hope that if we say it well enough we'll genuinely buy it too. Every prophet, intellectual, preacher, and professor is speaking out of need. They are trying to believe something in the hope that it will make them fully real. A fully actualized person would probably rarely speak at all.