It is important to keep in mind that there is only one valid interpretation of the evidence.
I'm going to have to disagree here.
Scripture is clear that there is one faith. (Eph 4:4) One doctrine (Romans 6:17), one path to heaven (Matthew 7:14). Look around you. There are literally hundreds of denominations out there, all teaching their own slant on how to get to heaven. We cannot approach God with our own righteousness (Romans 10:3). It must be according to His. The teachings of men bear the consequence of vain worship (Mark 7:7). We are forbidden to go beyond what is written (1 Corinthians 4:6), those who go too far have not God (2 John 9).
We are commanded to rightly handle the word of God (2 Timothy 2:15). The command to rightly handle the word of God directly infers that it can be handled incorrectly. And sadly many do.
First of all, we have slipped over from drawing conclusions to interpreting the evidence.
The bottom line is, we are each individually responsible for our own walk with God (Philippians 2:12) When you stand before the judgment seat, it's not going to be my interpretation or anybody else's that is going to be in consideration. It's going to be yours. Truth is not subjective by any means.
Also, the idea that there is a "right answer" to every question has not been demonstrated.
Common sense tells is that there is only one right answer to a doctrinal question. Baptism is either for the remission of sins or it isn't. One must either repent in order to be saved or they don't. One must either confess Jesus Christ as the Son of God or they don't. One must either have faith or not. There is no middle ground. There is no room for man's interpretations here. These things are absolutes.
In fact, Paul deflates that balloon in speaking of observing special religious days. Rather than provide the "one valid interpretation" so all would know whether we should observe the Sabbath, or Sunday, or the Feast of Tabernacles, he simply tells the brothers that each should be convinced in his own mind.
There is no hint in Romans 14:5 that Paul is referring to Sabbath days or other days observed under the law of Moses. You are reading more into that passage than is there. Paul does refer to the observance special days under the law of Moses in Galatians and they are condemned for it. Galatians 4:10-11
David's statement also seems to indicate that for any question to which we apply scripture, the scripture provides a definitive answer. History does not lead me to believe this, nor does the Bible itself make such a promise. If such a promise does exist, it is in Jesus' promise of the Holy Spirit to the believers, not in our own interpretive skills.
People have been abusing scripture for centuries. That started way before Jesus Christ arrived on earth. The interpretations of those in History are not a sound rule to judge by nor do their errors in any way validate unsound Biblical interpretation today. Truth is truth and there is error. That which is not truth is error.
And the Bible tells us we can know the truth (John 8:32). Those who diligently keep the commandments of God know they are of the truth (1 John 3:19 and context). It's not at all complicated. Obedience, by faith, is the key to everything.
I may be reading you wrong here, David, so please correct me if I have, but the sense I get from your post is that our central problem in coming to consensus on the will of God is an unwillingness to obey God. While none of us is immune to wanting our own way, I am hesitant to explain why you may disagree with how I read scripture as a matter of you (or I) being too self-willed to submit to God. That kind of judgment is too easy, and leads us back to that rather malicious accusation that if others would just be willing to obey God, they would see things as I do.
I am not at all malicious nor trying to be. Obedience to the will of God is a matter of life and death to a faithful Christian. One of the results of the false doctrine of salvation by faith alone is the rise of numerous denominations of people who think they are in a saved state when they are not. The importance of obedience to the will of God is lowered in priority. In the minds of those who believe in salvation by faith alone, obedience to the will of God is not a life and death matter, therefore it is not their priority. They often times give it lip service, but in reality, when it comes right down to it, they believe they are saved by their faith alone and when it comes to a sacrifice, a real sacrifice, they may rest in the false security of salvation by faith alone instead of making the personal sacrifice.
As for Biblical interpretation, the same thing applies. If you approach scripture from the perspective that it will cost you your eternal soul if you get it wrong and that your home in heaven depends on getting it right, then this whole thing of Biblical interpretation rises in importance to a level of urgency. A mistake in interpretation may well land you in the lake of fire for an eternity from which there is no escape. But to the person who believes they are saved by faith alone, getting it correct is not such a matter of urgency.
I used faith alone because this is an interpretation of scripture. It is a conclusion drawn by many, based on inferences drawn on specific passages in scripture. The Bible never makes the statement that anyone is saved by faith alone. In fact it says the exact opposite, denying it in words impossible to misunderstand in James chapter 2. Yet despite such clear language, millions and millions of people continue to hold to this false doctrine which has been inferred from scripture but never taught. And these people are heading to their judgment, believing a lie, and are going to be saddened when they hear exactly what Jesus said they would hear in Matthew 7:21.
If everybody approached the interpretation of scripture with the attitude that it is of life and death importance, and that the failure to correctly interpret it could cost them their eternal souls, I guarantee that we would start seeing denominations disappear and witness a wholesale exodus of people to the truth.