The first thing Paul tells the church to do in the short term, in order to reach maturity in Christ in the long term, is to stop being like a child in his inconsistency and naivete. The second thing comes in the first part of verse 15:
But speaking the truth in love …
Now, the Greek here is interesting. There’s no verbal “speaking”; the verb is rather simply the verbal form of the noun “truth.” We might translate it (woodenly) as “truthing.” “Speaking the truth” is not a bad translation—that’s ordinarily how one puts truth into action—but the word has a broader reference. We should be the truth; we should live the truth. We should be true to who (and whose) and what we are.
We should be true.
This in contrast to the childlikeness that Paul has just used to illustrate his point. Children are easily deceived; we shouldn’t be. Why is that? Because we know the truth; it governs our thinking and consequently our decisions and our actions.
We know that quarters don’t come out of our ears. We know that no one can know—without some kind of mischief—that we’re thinking of a grey elephant from Denmark.
And similarly, we know that discounting the value of the Scripture, or of the person or work of Christ, or of the legitimate unity of God’s people, does not come from those who are interested in God’s cause or our good.
We didn’t just fall off the turnip truck. This isn’t our first rodeo. We know better.
And why do we know better?
Because we know the Scripture, because we have pored over it and immersed our thoughts in it and rolled its truths over repeatedly in our minds, for the decades since he gave us spiritual life. And because we know Christ, both by that time and effort in the Scripture and by our daily walk and communion with him over those same decades.
I’ve been married for over 38 years. Each year I learn more about my wife, both because I’m a slow learner and because she has grown and changed since we began our life together. And now, approaching 4 decades of daily interaction, I know a lot about her. Because of that knowledge I don’t wonder what she’s going to think about this or that, or how she’s going to react to a given situation, or whether she’s likely to do something inappropriate.
I know her. And that answers a lot of questions even as it calms—or dismisses—a lot of potential fears.
If somebody tells me something about her that isn’t true, I’m pretty sure I’m not going to believe it.
Because I know her.
Now, I’ve known the Father, the Son, and the Spirit almost twice as long as I’ve known my wife. Shame on me if I fall for some lie about him, or some distortion of his motives or his ways. Shame on me if I start to believe that he isn’t good, or that his inaction demonstrates his inattention or his apathy.
And shame on us, his church, his people, if we find ourselves distracted by relatively trivial, temporary causes, or divided by temporary social or political issues, hating one another because of our support for this or that candidate or plebiscite or ballot initiative, or the color of our hats.
We need to see things as they are from the perspective of the one who lives forever and who has been working his great and gracious plan from before the world was.
We need to give our energies to that eternal plan.
We need to grow up.