As you can see, this girl was trying desperately to draw a line between matters of faith and things that fall in the category of math and science. She was trying to say that faith is merely a personal choice, like which ice cream flavor is best. But God either exists or He doesn't. Jesus of Nazareth either really lived, really was crucified, and really rose from the dead or He didn't. These statements aren't nearly the same as liking a particular ice cream. They are questions of history and of existence. That means they can be investigated and facts can be discovered. Reasons for their truth or falsehood can be offered. And if it's found that there are good reasons for believing in these claims, then we are only unreasonable if we refuse to believe them.
So reason and faith are not opposites. The Christian faith rests upon the reasons we have for believing in things like the resurrection. In our Proverbs passage, God says that we are to cling to "the words of the wise"; we are to cling to "excellent things of counsels and knowledge." Wise words, counsels, and knowledge are all objective terms; words are only wise or knowledgeable if they are true. And if something is true, then it must be rational to hold to such as belief. That's why God says we can know the certainty of the word of truth. To do anything else would be irrational!