Be afflicted and mourn. Christ denounces mourning on those who laugh, as a curse, (Luke 6:25;) and James, in what shortly follows, alluding to the same words, threatens the rich with mourning. But here he speaks of that salutary mourning or sorrow which leads us to repentance. He addresses those who, being inebriated in their minds, did not perceive God's judgment. Thus it happened that they flattered themselves in their vices. That he might shake off from them this deadly torpor, he admonishes them to learn to mourn, that being touched with sorrow of conscience they might cease to flatter themselves and to exult on the verge of destruction. Then laughter is to be taken as signifying the flattering with which the ungodly deceive themselves, while they are infatuated by the sweetness of their sins and forget the judgment of God.

Be afflicted, and mourn, and weep - That is, evidently, on account of your sins. The sins to which the apostle refers are those which he had specified in the previous part of the chapter, and which he had spoken of as so evil in their nature, and so dangerous in their tendency. The word rendered "be afflicted" means, properly, to endure toil or hardship; then to endure affliction or distress; and here means, that they were to afflict themselves - that is, they were to feel distressed and sad on account of their transgressions. Compare Ezra 8:21. The other words in this clause are those which are expressive of deep grief or sorrow. The language here used shows that the apostle supposed that it was possible that those who had done wrong should voluntarily feel sorrow for it, and that, therefore, it was proper to call upon them to do it.
(All who feel true sorrow for sin, do so voluntarily; but it is not intended by this assertion to insinuate that repentance is not the work of the Spirit. He operates on men without destroying their freedom, or doing violence to their will: "in the day of his power they are willing." Nor is it improper to call on men to do that for which they require the Spirit's aid. That aid is not withheld in the hour of need; and everywhere the Bible commands sinners to believe and repent.)
Let your laughter be turned to mourning - It would seem that the persons referred to, instead of suitable sorrow and humiliation on account of sin, gave themselves to joyousness, mirth, and revelry. See a similar instance in Isaiah 22:12-13. It is often the case, that those for whom the deep sorrows of repentance would be peculiarly appropriate, give themselves to mirth and vanity. The apostle here says that such mirth did not become them. Sorrow, deep and unfeigned, was appropriate on account of their sins, and the sound of laughter and of revelry should be changed to notes of lamentation. To how many of the assemblies of the vain, the gay, and the dissipated, might the exhortation in this passage with propriety be now addressed!
Your joy to heaviness - The word here rendered heaviness occurs nowhere else in the New Testament. It means dejection, sorrow. It is not gloom, melancholy, or moroseness, but it is sorrow on account of sin. God has so made us that we should feel sorrow when we are conscious that we have done wrong, and it is appropriate that we should do so.

Be afflicted, and mourn - Without true and deep repentance ye cannot expect the mercy of God.
Let your laughter be turned to mourning - It appears most evidently that many of those to whom St. James addressed this epistle had lived a very irregular and dissolute life. He had already spoken of their lust, and pleasures, and he had called them adulterers and adulteresses; and perhaps they were so in the grossest sense of the words. He speaks here of their laughter and their joy; and all the terms taken together show that a dissolute life is intended. What a strange view must he have of the nature of primitive Christianity, who can suppose that these words can possibly have been addressed to people professing the Gospel of Jesus Christ, who were few in number, without wealth or consequence, and were persecuted and oppressed both by their brethren the Jews and by the Romans!

(6) Be afflicted, and mourn, and weep: let your laughter be turned to mourning, and [your] joy to (a) heaviness.
(6) He goes on in the same comparison of opposites, and contrasts those profane joys with an earnest sorrow of mind, and pride and arrogancy with holy modesty.
(a) By this word the Greeks mean a heaviness joined with shamefacedness, which is to be seen in a cast down countenance, and settled as it were upon the ground.

Be afflicted, and mourn, and weep,.... Not in a bare external way; not by afflicting the body with fastings and scourgings, by renting of garments, and clothing with sackcloth, and putting ashes on the head, and other such outward methods of humiliation; but afflicting the soul is meant, an inward mourning and weeping over the plague of the heart, the impurity of nature, and the various sins of life; after a godly sort, and because contrary to a God of infinite love and grace; in an evangelical way, looking to Jesus, and being affected with the pardoning grace and love of God in Christ.
Let your laughter be turned to mourning, and your joy to heaviness; meaning their carnal joy, on account of their friendship with the world, and their enjoyment of the things of it, since they consumed them on their lusts, and which betrayed enmity to God.

Be afflicted--literally, "Endure misery," that is, mourn over your wretchedness through sin. Repent with deep sorrow instead of your present laughter. A blessed mourning. Contrast Isaiah 22:12-13; Luke 6:25. James does not add here, as in James 5:1, "howl," where he foretells the doom of the impenitent at the coming destruction of Jerusalem.
heaviness--literally, "falling of the countenance," casting down of the eyes.

Be afflicted - For your past unfaithfulness to God.