First, the greatest joy of believers is hearing that souls we've labored for are walking in the truth. Vs4, "I have no greater joy than to hear that my children are walking in the truth."

This enlightens us to the new joys of a kingdom that's not of this world. We are new creations, made so by Christ, and we rejoice in God's word and work. We get the gospel in, so we can get it out. God gives us joy by the Holy Spirit. Jesus said, “The kingdom of God does not come with observation; nor will they say, ‘See here!’ or ‘See there!’ For indeed, the kingdom of God is within you [Luke 17:20-21].”

It's not possessions. It's communion with God in doing good, and seeing our labors blessed, which thrills us. Therefore, let us seek this new joy by living all out for Christ.

Gaius is an example of this goodness [vs1-3]. He used his resources to serve others. John prays for his prosperity, even as his soul prospered, because he used what he had for God. This is walking in the truth, and in love.

Secondly, support those who preach the gospel, especially missionaries, who have abandoned themselves to the gospel. 3 John 1:7-8, "for they began their journey for the sake of Christ, accepting no support from non-believers. Therefore we ought to support such people, so that we may become co-workers with the truth." They don't take from unbelievers, nor do they preach for money. They're on mission to glorify God and save sinners in hostile lands and under adverse circumstances. They are living for others to be saved.

Support them tangibly with giving. Assist them on their journey, and co-labor with them. You can't go yourself. You have not been called. You work with them, however, side by side, when you meet their material needs, so they can preach.

This is an honor and privilege. It enables us to labor with God, and do the GREATEST BENEFIT to our fellow man! What can be greater than bringing sinners to Christ, who redeemed them with his blood?

Thirdly, the testimony of scriptures is true. Judge everyone by his deeds.

3 John 1:9-12, "I have written something to the church; but Diotrephes, who likes to put himself first, does not acknowledge our authority. So if I come, I will call attention to what he is doing in spreading false charges against us. And not content with those charges, he refuses to welcome the friends, and even prevents those who want to do so and expels them from the church. Beloved, do not imitate what is evil but imitate what is good. Whoever does good is from God; whoever does evil has not seen God. Everyone has testified favorably about Demetrius, and so has the truth itself. We also testify for him, and you know that our testimony is true."

Don't be deceived by talk. Men can love Arthur Pink's, The Sovereignty of God, and yet live murmuring. They can preach God's love, and yet be hateful, gossiping and slandering their brother enviously. They can, like Diotrephes, love to have the preeminence, and forbid the Apostle's doctrine of love and truth. They can oppose the truth, even while speaking truth like Balaam. Judge a person's whole character. If it lines up with scripture, then great. If not, reject them.

This is serious. Don't be timid. Those who repent, deal with them graciously, considering yourself. Those that remain obstinate, rebuke openly.

The gospel must go forward in true love. We don't want to be shams, and we don't want anything to do with them. They are the mission field, but not brothers.