3 John 1:2

He wishes that in all things he may prosper. "Above all things" goes too far. Some have taken up the extreme idea that it makes no difference how badly our affairs go, or how poor our health is — the only concern is that the soul should prosper. The apostle, writing by inspiration, does not support such fanaticism… He carefully gives first place to the soul's welfare. If that welfare is guarded and real, we can as a general rule count on the Lord's interest in what we undertake or in our business, and in our health. If the soul prospers, our gracious God takes pleasure in us and in everything that concerns us. The very hairs of our head are all numbered.

In the second verse John testifies that Gaius's soul prospered so much that he could only wish his body might be as healthy as his soul… For most of us the health of the body is better than the health of the soul. We meet one another and ask, How are you? We take it for granted that the question is about the body, so we answer cheerfully (as a rule), Quite well, thank you. But if the question were, How is it with your soul? — what would we say?

The word translated here "be in health" also appears in Luke 7:10 and 15:27, where the King James translation renders it "whole" and "safe and sound". When Paul wrote to the church in Thessalonica, he prayed that their whole spirit and soul and body be kept blameless at the coming of our Lord Jesus Christ (1 Thess. 5:23).

Gaius was probably weak in body. Even so, he clearly did not plead that as a reason to ease off in his service. Note too, since it touches a common error, that there is no necessary link between our spiritual condition and our bodily condition. Many now accept that all bodily weakness and disease are signs of a bad state of soul. But this inspired prayer for Gaius shows at once that such a claim is not scriptural.

Sometimes, so that the soul may prosper, God dries up the thing we are too taken up with. If that is not enough, He disciplines us with bodily sickness… Sometimes He sets a keen worker aside so that he may learn that God can carry on His work without him. That man has been busy reaching and preaching to others, and has grown less watchful over his own communion with God. The Lord in His goodness and love corrects him, and turns a little sickness to much good. But here, since Gaius was prospering in soul, the apostle wishes him prosperity in everything else and in his body too.

John did not learn of Gaius's spiritual prosperity by meeting him, for he was far away and writing to him by letter. Others told him. Some believers had arrived in John's area and spoke of Gaius. What they said showed that the truth was living in him, and that it came out in his life, for he walked in truth. What is in us comes out in what we do.

He wishes Gaius to prosper as well as to be in health. Gaius stood out, like some dear believers today, in every kind of Christian hospitality… John could then wish him full health and prosperity, because his prosperity served God's people.