Belief may be either rational, or assumed on faith. But in either case, it doesn't matter how convinced you are; belief does not equal knowledge. The difference is that knowledge can always be tested for accuracy where mere beliefs often can not be. No matter how positively you think you know it, if you can't show it, then you don't know it, and you shouldn't say that you do. Nor would you if you really cared about the truth. Knowledge is demonstrable, measurable. But faith is often a matter of pretending to know what you know you really don't know, and that no one even can know, and which you merely believe -often for no good reason at all.

"4th Foundational Falsehood of Creationism", Youtube (December 25, 2007) - Foundational Falsehoods of Creationism

4th Foundational Falsehood of Creationism