3 For I rejoiced greatly when the brothers came and testified to your truth, as indeed you are walking in the truth.
4 I have no greater joy than to hear that my children are walking in the truth. – 3 John 1:3-4
Verse 3 begins with the word for, tying this back to what John has just said in verse 2 about his knowledge that Gaius was spiritually healthy. What follows for is how he is confident of this.
The reason why he knows that Gaius was spiritually healthy is that he rejoiced greatly when the brothers came and testified to Gaius’s truth. Other Christians, probably the missionaries he will mention later in the letter, were raving about Gaius’s faithfulness to Christlike living. This is what John is likely talking about when he refers to Gaius’s truth: Gaius’s adherence to what Jesus taught, being Himself the Truth.
The brothers testified to Gaius’s truth, as indeed he was walking in the truth. It wasn’t merely that he believed the right doctrines, but also lived accordingly. And this brought John great joy.
In fact, John writes that he has no greater joy than to hear that his spiritual children, those believers whom he helped mature in the Lord, are walking in the truth. To John, this is the pinnacle of joy, to see brothers and sisters living faithfully in Christ.
Oh, that we would have this attitude toward one another. One of our greatest joys in our lives ought to be the spiritual well-being of one another. It’s also implied that it was one of John’s most important goals, and it ought be one for us also.
Discipleship is something we tend to push to the side, but instead, it should take priority. And it will take priority if we would have no greater joy than to see our brothers and sisters walking in the truth. We would pursue that joy by doing everything we can by God’s grace to have it.
So, may we rejoice to see others thriving in the Lord, and may we thus do what we can to raise others up to that end.