Scripture is true because the Holy Spirit tells me it is. However, Scripture confirms what the Holy Spirit says, and when it doesn't, then that voice may not be the Holy Spirit. In the case of theistic evolution, scripture confirms none of it.
So, if you ask God if the Bible is true and He says yes, then it is true. But if He says no, then it wasn't him. So why bother asking if you will only accept one answer? And how does that allow God the chance to correct possible misinterpretations of those that taught their understanding of the Bible to you?
Bottom line is you believe because someone else told you to, and you are not allowed to disbelieve them. You are either lazy or afraid. Either way you have no faith of your own.