You're right,
@VeritatisVerba, that reason is involved in interpretation. However, it makes a huge difference whether or not you add ideas and assumptions outside of Scripture to the passages that you're trying to interpret.
I grew up in a church that didn't preach the gospel and that was either liberal in denying that God inspired the Bible and embracing being "good people" or neo-orthodox in allegorizing much of it because they didn't like what it says. Then, after I became a Christian in a Baptist church, where I heard the gospel for the first time, I attended a cult that did a lot of imposing of extra-biblical ideas on the Bible by denying the Trinity and the history. I became a pastor in a denomination that is very close to the Bible's teachings without adding to them. Now, I attend just such an independent church.
That's why I've become very sensitive to ways people misuse Scripture.
You cannot detect a misuse of Scripture without sound reason.
The point I am making is that Scripture does not trump reason. There is no such thing as an irrational truth. The Bible is a book, and like all books, it is language-based. Language itself is a rational construct. That means the Bible depends on reason in order to even exist, never mind be understood and integrated into our worldview and applied to our daily lives. Scripture then is predicated on reason, NOT the other way around. If someone claims to honor God’s word while setting aside sound reasoning, then they are undermining the very foundation that God’s word is built on. Trying to know the meaning of Scripture without reason is like trying to admire a rainbow with your eyes closed. It cannot be done.
Let me pose a question.
What should a person do when they discover that a doctrine they’ve long held turns out, upon careful reflection, to be internally contradictory? I don’t have a specific doctrine in mind, just think through the question as asked.
There are a few ways one might respond.
One could acknowledge that the internal contradiction calls the doctrine into question and that further study is necessary. That is the rational and responsible course.
One could dismiss the contradiction and cling to the doctrine anyway, claiming that Scripture teaches it and that faith requires belief even in the face of unresolved inconsistency. That is not faithfulness, it is evasion and dishonesty.
Or one might try to find a way to resolve the contradiction by redefining terms, appealing to mystery, or introducing qualifications. Sometimes such efforts are appropriate, other times they are plainly not. The key is whether the resolution is coherent or simply a way to camouflage the contradiction. The difference there being primarily one of intellectual honesty. It's the difference between reasoning and rationalizing.
For anyone who truly seeks the truth, sound reason must be the standard. If we abandon that, then we have no means of distinguishing true doctrine from false, or even meaning from nonsense. Without it, the phrase, "sound doctrine" means anything at all and, therefore, nothing whatsoever.