I’ve taught seminary students for more than three decades. If there are two principles for biblical interpretation that I’ve hammered home time and again, it would be these two: 1) Let Scripture interpret Scripture; and 2) Don’t take verses/passages out of context.
Just think about the opening words of III John:
“This letter is from John, the elder.
“I am writing to Gaius, my dear friend, whom I love in the truth.
“Dear friend, I hope all is well with you and that you are as healthy in body as you are strong in spirit.” (III John 1-2, NLT)
At first glance, you might think there’s not much there to exegete. And you would be right. It’s a fairly generic greeting, using standard niceties of the day between two good friends: “I hope you’re as healthy in body as you are strong in spirit.” That was like a standard, “Hello, hope everything is good with you and your family” or, “I hope this finds you doing well.”
But some have taken it to mean something more. That it’s not a greeting, but rather a declaration or a statement: If you are sound in spirit, you will be healthy in body. If you’re spiritually healthy, you’ll be physically healthy. And not just physically healthy, but materially well-off as well. This is, of course, the “health and wealth” gospel. And this is, of course, not what John was saying. He wasn’t trying to say anything theologically prescriptive at all. He was just starting off a letter with a common greeting of the day. We know this because the same kind of greeting was widely used in letters and correspondence during that time. He knew that Gaius was doing well spiritually, so he just opened up by saying, “I hope and pray that you are feeling/doing as well as I know you are doing with Christ.”
This is where our interpretive principles come into play. First, letting Scripture interpret Scripture. If John was saying something as significant and provocative as the guarantee of health and wealth if you walk closely with Christ, that would be major doctrine—not to mention an overarching principle taught clearly throughout Scripture. Yet it isn’t. That should, then, lead everyone to be careful not to read too much into an opening greeting like this, particularly something as sweeping as the idea of health and wealth being tied to your relationship with Jesus.
God can certainly bring about material blessing. He can certainly heal us. But it is also true that some of the greatest saints in the Bible faced all kinds of persecution and poverty and difficulties. So that ought to make us pause right there before reading anything more than a greeting into the opening lines of III John.
Then comes our second principle. In addition to letting Scripture interpret Scripture, we must ensure that we never take a verse out of its context. Again, III John serves as a good example. John is writing to address an internal issue within the church relating to a major personality conflict with a man named Diotrephes. There is nothing in the letter about the problem of pain, or evil, or poverty, or about how a walk with God brings success or wealth. So to read that into the greeting would not be exegesis, which is discovering what the text itself says, but eisegesis, which is adding to what the text itself says.