Seem to be religious. He now reproves even in those who boasted that they were doers of the law, a vice under which hypocrites commonly labor, that is, the wantonness of the tongue in detraction. He has before touched on the duty of restraining the tongue, but for a different end; for he then bade silence before God, that we might be more fitted to learn. He speaks now of another thing, that the faithful should not employ their tongue in evil speaking. It was indeed needful that this vice should be condemned, when the subject was the keeping of the law; for they who have put off the grosser vices, are especially subject to this disease. He who is neither an adulterer, nor a thief, nor a drunkard, but, on the contrary, seems brilliant with some outward shew of sanctity will set himself off by defaming others, and this under the pretense of zeal, but really through the lust of slandering. The object here, then, was to distinguish between the true worshippers of God and hypocrites, who are so swollen with Pharisaic pride, that they seek praise from the defects of others. If any one, he says, seems to be religious, that is, who has a show of sanctity, and the meantime flatters himself by speaking evil of others, it is hence evident that he does not truly serve God. For by saying that his religion is vain, he not only intimates that other virtues are marred by the stain of evil-speaking, but that the conclusion is, that the zeal for religion which appears is not sincere. But deceiveth his own heart. I do not approve of the version of Erasmus -- "But suffers his heart to err;" for he points out the fountain of that arrogance to which hypocrites are addicted, through which, being blinded by an immoderate love of themselves, they believe themselves to be far better than they really are; and hence, no doubt, is the disease of slandering, because the wallet, as Aesop says in his Apologue, hanging behind, is not seen. Rightly, then, has James, wishing to remove the effect, that is, the lust of evil-speaking, added the cause, even that hypocrites flatter themselves immoderately. For they would be ready to forgive were they in their turn to acknowledge themselves to be in need of forgiveness. Hence the flatteries by which they deceive themselves as to their own vices, make them such supercilious censors of others.

If any man among you seem to be religious - Pious, or devout. That is, if he does not restrain his tongue, his other evidences of religion are worthless. A man may undoubtedly have many things in his character which seem to be evidences of the existence of religion in his heart, and yet there may be some one thing that shall show that all those evidences are false. Religion is designed to produce an effect on our whole conduct; and if there is any one thing in reference to which it does not bring us under its control, that one thing may show that all other appearances of piety are worthless.
And bridleth not his tongue - Restrains or curbs it not, as a horse is restrained with a bridle. There may have been some reason why the apostle referred to this particular sin which is now unknown to us; or he may perhaps have intended to select this as a specimen to illustrate this idea, that if there is any one evil propensity which religion does not control, or if there is any one thing in respect to which its influence is not felt, whatever other evidences of piety there may be, this will demonstrate that all those appearances of religion are vain. For religion is designed to bring the whole man under control, and to subdue every faculty of the body and mind to its demands. If the tongue is not restrained, or if there is any unsubdued propensity to sin whatever, it proves that there is no true religion.
But deceiveth his own heart - Implying that he does deceive his heart by supposing that any evidence can prove that he is under the influence of religion if his tongue is unrestrained. Whatever love, or zeal, or orthodoxy, or gift in preaching or in prayer he may have, this one evil propensity will neutralize it all, and show that there is no true religion at heart.
This man's religion is vain - As all religion must be which does not control all the faculties of the body and the mind. The truths, then, which are taught in this verse are:
(1) That there may be evidences of piety which seem to be very plausible or clear, but which in themselves do not prove that there is any true religion. There may be much zeal, as in the case of the Pharisees; there may be much apparent love of Christians, or much outward benevolence; there may be an uncommon gift in prayer; there may be much self-denial, as among those who withdraw from the world in monasteries or nunneries; or there may have been deep conviction for sin, and much joy at the time of the supposed conversion, and still there be no true religion. Each and all of these things may exist in the heart where there is no true religion.
(2) a single unsubdued sinful propensity neutralizes all these things, and shows that there is no true religion. If the tongue is not subdued; if any sin is indulged, it will show that the seat of the evil has not been reached, and that the soul, as such, has never been brought into subjection to the law of God. For the very essence of all the sin that there was in the soul may have been concentrated on that one propensity. Everything else which may be manifested may be accounted for on the supposition that there is no religion; this cannot be accounted for on the supposition that there is any.

Seem to be religious - The words θρησκος and θρησκεια, which we translate religious and religion, (see the next verse), are of very uncertain etymology. Suidas, under the word θρησκευει, which he translates θεοσεβει, ὑπηρετει τοις θεοις, he worships or serves the gods, accounts for the derivation thus: "It is said that Orpheus, a Thracian, instituted the mysteries (or religious rites) of the Greeks, and called the worshipping of God θρησκευειν threskeuein, as being a Thracian invention." Whatever its derivation may be, the word is used both to signify true religion, and superstition or heterodoxy. See Hesychius, and see on James 1:27 (note).
Bridleth not his tongue - He who speaks not according to the oracles of God, whatever pretences he makes to religion, only shows, by his want of scriptural knowledge, that his religion is false, ματαιος, or empty of solid truth, profit to others, and good to himself. Such a person should bridle his tongue, put the bit in his mouth; and particularly if he be a professed teacher of religion; ho matter where he has studied, or what else he has learned, if he have not learned religion, he can never teach it. And religion is of such a nature that no man can learn it but by experience; he who does not feel the doctrine of God to be the power of God to the salvation of his soul, can neither teach religion, nor act according to its dictates, because he is an unconverted, unrenewed man. If he be old, let him retire to the desert, and pray to God for light; if he be in the prime of life, let him turn his attention to some honest calling; if he be young, let him tarry at Jericho till his beard grows.

(18) If any man among you seem to be religious, and bridleth not his tongue, but deceiveth his (y) own heart, this man's religion [is] vain.
(18) The third admonition: the word of God lays down a rule to not only do well, but also to speak well.
(y) The fountain of all babbling, cursed speaking, and impudence is this, that men do not know themselves.

If any man among you seem to be religious,.... By his preaching, or praying, and hearing, and other external duties of religion, he is constant in the observance of; and who, upon the account of these things, "thinks himself to be a religious man", as the Vulgate Latin, Syriac, and Arabic versions render it; or is thought to be so by others:
and bridleth not his tongue; but boasts of his works, and speaks ill of his brethren; backbites them, and hurts their names and characters, by private insinuations, and public charges without any foundation; who takes no care of what he says, but gives his tongue a liberty of speaking anything, to the injury of others, and the dishonour of God, and his ways: there seems to be an allusion to Psalm 39:1.
But deceiveth his own heart; with his show of religion, and external performances; on which he builds his hopes of salvation; of which he is confident; and so gives himself to a loose way of talking what he pleases:
this man's religion is vain; useless, and unprofitable to himself and others; all his preaching, praying, hearing, and attendance on the ordinances will be of no avail to him; and he, notwithstanding these, by his evil tongue, brings a scandal and reproach upon the ways of God, and doctrines of Christ.

When men take more pains to seem religious than really to be so, it is a sign their religion is in vain. The not bridling the tongue, readiness to speak of the faults of others, or to lessen their wisdom and piety, are signs of a vain religion. The man who has a slandering tongue, cannot have a truly humble, gracious heart. False religious may be known by their impurity and uncharitableness. True religion teaches us to do every thing as in the presence of God. An unspotted life must go with unfeigned love and charity. Our true religion is equal to the measure in which these things have place in our hearts and conduct. And let us remember, that nothing avails in Christ Jesus, but faith that worketh by love, purifies the heart, subdues carnal lusts, and obeys God's commands.

An example of doing work.
religious . . . religion--The Greek expresses the external service or exercise of religion, "godliness" being the internal soul of it. "If any man think himself to be (so the Greek) religious, that is, observant of the offices of religion, let him know these consist not so much in outward observances, as in such acts of mercy and humble piety (Micah 6:7-8) as visiting the fatherless, &c., and keeping one's self unspotted from the world" (Matthew 23:23). James does not mean that these offices are the great essentials, or sum total of religion; but that, whereas the law service was merely ceremonial, the very services of the Gospel consist in acts of mercy and holiness, and it has light for its garment, its very robe being righteousness [TRENCH]. The Greek word is only found in Acts 26:5, "after the straitest sect of our religion I lived a Pharisee." Colossians 2:18, "worshipping of angels."
bridleth not . . . tongue--Discretion in speech is better than fluency of speech (compare James 3:2-3). Compare Psalm 39:1. God alone can enable us to do so. James, in treating of the law, naturally notices this sin. For they who are free from grosser sins, and even bear the outward show of sanctity, will often exalt themselves by detracting others under the pretense of zeal, while their real motive is love of evil-speaking [CALVIN].
heart--It and the tongue act and react on one another.

If any . . . seemeth to be religious. He who professes religion and yet does not control his tongue is deceived. Unless he has grace enough to rule the unruly member, he has not enough for salvation.
Pure religion and undefiled. Combining pure hearts and pure outward lives. This genuine religion has two elements: (1) Kind and loving deeds, exemplified especially in helping the helpless, such as widows and orphans, and (2) living pure, unsullied lives, unstained by the sins prevalent in this sinful world.

If any one be ever so religious - Exact in the outward offices of religion. And bridleth not his tongue - From backbiting, talebearing, evilspeaking, he only deceiveth his own heart, if he fancies he has any true religion at all.