Practice vs. Principle

From this talk by Austin Duncan at the 2012 Shepherd's Conference (emphasis mine):

When you translate that [biblical] principle into a specific action and decision and seek to call it still a principle rather than an application of a principle, you can find yourself in a position like the false teachers that Ezekiel dealt with saying "Thus saith the Lord" when the Lord hath not said...

You can honor the principle and have different practices, and the beauty of the Body of Christ is that there should be people in your church who disagree on some things but love each other extravagantly because they have a common faith. They do things differently; they come from different backgrounds.

If you think your niche view of dating is God's view of dating, I want you to see if that translates to 5000 years ago, and I want you to see if it translates 1000 years ago, and I want you to take it to India and see if it works, because God's word is true then and now, here and there. And when you force your particular methodology and make your practice into a principle, you are going to wreak havoc on a church community, on a body of believers, and I can't see anything in the New Testament that God holds by way of personal and practical application in the church higher than Christian unity...

We are going to put those principles into practice different ways, but we want to be a people who take God's word seriously. The strength of being someone who preaches for application can be a dangerous practice in your church when it gets elevated and invested with the authority that this alone ought to have. This is what the Pharisees did. They burdened people with man-made regulations that aren't commanded in God's Word. God's word handled rightly will lead to automatic humble, wise, Holy Spirit-led application in the lives of believers, and there isn't just one application.

This talk was given to pastors on dating/courtship but I think his point is worth noting for listeners and readers regarding a variety of subjects.

Why? Because how-to's are easier. Tell me how to solve my (fill in the blank) problem for which there is no shortage of written and verbal advice. If it's a non-spiritual issue, such as how to rid my yard of voles, it's easy to take the recommendations with a grain of salt. But if it's a Christian issue, it's easy to confuse an author/speaker's practice as a principle especially when Scripture is invoked  to substantiate said practice.  After all, who am I to contradict God's word?  Plus, I want to bank on that authority because I want the same result.

As a brand-new mom, I remember trying to follow a popular Christian parenting program that would have my baby sleeping through the night in one month or however long they said it would take. It was all the rage because it was "biblically"-based. It worked for the authors; it worked for my friends, but it didn't work for me. This led to frustration with myself and my daughter. On top of being exhausted and suffering from new-mom-cluelessness, there was the added burden of wondering if I was spoiling her because she still needed to be fed at night.  We shortly ditched the method after a mother of eight kindly told me, "She's just hungry. Babies need to eat."

So when it comes to application, I'm taking a good-sized grain of salt and evaluating what I read and hear. Is it practice or principle? Is it valid "then and now, here and there"? Even with the best credentials and reputation and even if there's merit to the advice, one person's practice is not synonymous with God's Word.