Imagine you own a home and are excavating part of your backyard to put in an in-ground pool. While the digging is going on, your neighbor storms up and declares that the hole in the ground crosses the boundary between your property and his, so you are stealing some of his property. Now, you could reply philosophically, “Well, as I see it the line goes here, but I respect that you see it over there, and maybe you’re right—who can say? In the end these details really aren’t the most important thing. The important thing is that we always get along as neighbors (and that I have a pool).” But of course you wouldn’t say that! Not only will you not appease your neighbor that way, but there are real legal and financial consequences for you if you actually did start digging in his yard. Even if you’re nice about it, you would still strongly defend your understanding of where the property line goes, because it really matters which side of it your pool is on.
We live in a world where people who are very keen on real estate property lines are very fuzzy on doctrine and theology, even many Christians. Doctrine can seem impossible to nail down with precision and impractical or unnecessary anyhow—sometimes the more impractical the more it is nailed down. And it turns people off when others get angry, unkind, and even violent about doctrinal differences. So most folks like to keep things blurry and say things like, “We may differ, but it doesn’t matter what we believe as long as we’re sincere.”
But in sharp contrast to this attitude, we Christians really care to get the details right about doctrine for the same reason that it’s important to know where the property lines are before you put in a pool. We need to know where the lines are, because there will be bad consequences for us if we’re on the wrong side of them. And we defend those lines because we don’t want to be lured away from what we need to survive and to thrive.
For example, the most repeatedly and hotly debated doctrine in the first eight centuries of the Church was the person of Christ—in other words, how “God” was Christ and how “man” was Christ, and how did the God part and the man part connect with each other in him? The further along the debate went and the more options were ruled out, the more technical and difficult to understand the issue became. But what kept the faithful going through the whole exhausting dispute was a conviction that our salvation hinged on it. If the single person who both died on the cross and rose from the dead were not fully God and fully human without confusion, change, division, or separation, then we could not be saved, because only that sort of person could bring us and God together. And to this day it matters—our salvation depends on this truth, so we had better know what it is and be sure about it or go off and find something better.
Mining the Bible for doctrinal details or stimulating each other in discussion in a Bible study might seem to some folks like a lot of work for a little payoff. Does it really do anyone any good? Without a doubt, if we talk endlessly about God’s Word but don’t do it, it doesn’t do any good. But if are obedient to what we know, it is essential. Knowing God’s truth, whatever it is, is as practical as planning how you’ll spend the next trillion or so years.