Rejoiceth not in iniquity - Does not rejoice over the "vices" of other people; does not take delight when they are guilty of crime, or when, in any manner, they fall into sin. It does not find pleasure in hearing others accused of sin, and in having it proved that they committed it. It does not find a malicious pleasure in the "report" that they have done wrong; or in following up that report, and finding it established. Wicked people often find pleasure in this Romans 1:32, and rejoice when others have fallen into sin, and have disgraced and ruined themselves. People of the world often find a malignant pleasure in the report, and in the evidence that a member of the Church has brought dishonor on his profession. A man often rejoices when an enemy, a persecutor, or a slanderer has committed some crime, and when he has shown an improper spirit, uttered a rash expression, or taken some step which shall involve him in ignominy. But love does none of these things. It does not desire that an enemy, a persecutor, or a slanderer should do evil, or should disgrace and ruin himself. It does not rejoice, but grieves, when a professor of religion, or an enemy of religion - when a personal friend or foe has done anything wrong. It neither loves the wrong, nor the fact that it has been done. And perhaps there is no greater triumph of the gospel than in its enabling a man to rejoice that even his enemy and persecutor in any respect does well; or to rejoice that he is in any way honored and respected among people. Human nature, without the gospel, manifests a different feeling; and it is only as the heart is subdued by the gospel, and filled with universal benevolence, that it is brought to rejoice when all people do well.
Rejoiceth in the truth - The word "truth" here stands opposed to "iniquity," and means virtue, piety, goodness. It does not rejoice in the "vices," but in the "virtues" of others. It is pleased, it rejoices when they "do well." It is pleased when those who differ from us conduct themselves in any manner in such a way as to please God, and to advance their own reputation and happiness. They who are under the influence of that love rejoice that good is done, and the truth defended and advanced, whoever may be the instrument; rejoice that others are successful in their plans of doing good, though they do not act with us; rejoice that other people have a reputation well earned for virtue and purity of life, though they may differ from us in opinion, and may be connected with a different denomination. They do not rejoice when other denominations of Christians fall into error; or when their plans are blasted; or when they are calumniated, and oppressed, and reviled.
By whomsoever good is done, or wheresoever, it is to them a matter of rejoicing; and by whomsoever evil is done, or wheresoever, it is to them a matter of grief; see -Philippians 1:14-18. The "reason" of this is, that all sin, error, and vice will ultimately ruin the happiness of anyone; and as love desires their happiness, it desires that they should walk in the ways of virtue, and is grieved when they do not. What a change would the prevalence of this feeling produce in the conduct and happiness of mankind! How much ill-natured joy would it repress at the faults of others? How much would it do to repress the pains which a man often takes to circulate reports disadvantageous to his adversary; to find out and establish some flaw in his character; to prove that he has said or done something disgraceful and evil! And how much would it do even among Christians, in restraining them from rejoicing at the errors, mistakes, and improprieties of the friends of revivals of religion, and in leading them to mourn over their errors in secret, instead of taking a malicious pleasure in promulgating them to the world! This would be a very different world if there were none to rejoice in iniquity; and the church would be a different church if there were none in its bosom but those who rejoiced in the truth, and in the efforts of humble and self-denying piety.

(10.)
Rejoiceth not in iniquity - Ου χαιρει επι τῃ αδικιᾳ· Rejoiceth not in falsehood, but on the contrary, rejoiceth in the truth: this meaning αδικια has in different parts of the Scriptures. At first view, this character of love seems to say but little in its favor; for who can rejoice in unrighteousness or falsity? But is it not a frequent case that persons, who have received any kind of injury, and have forborne to avenge themselves, but perhaps have left it to God; when evil falls upon the sinner do console themselves with what appears to them an evidence that God has avenged their quarrels; and do at least secretly rejoice that the man is suffering for his misdeeds? Is not this, in some sort, rejoicing in iniquity? Again: is it not common for interested persons to rejoice in the successes of an unjust and sanguinary war, in the sackage and burning of cities and towns; and is not the joy always in proportion to the slaughter that has been made of the enemy? And do these call themselves Christians? Then we may expect that Moloch and his sub-devils are not so far behind this description of Christians as to render their case utterly desperate. If such Christians can be saved, demons need not despair!
(11.)
But rejoiceth in the truth - Αληθεια· Every thing that is opposite to falsehood and irreligion. Those who are filled with the love of God and man rejoice in the propagation and extension of Divine truth - in the spread of true religion, by which alone peace and good will can be diffused throughout the earth. And because they rejoice in the truth, therefore they do not persecute nor hinder true religion, but help it forward with all their might and power.

Rejoiceth not in iniquity, but (f) rejoiceth in the truth;
(f) Rejoices at righteousness in the righteous. For by "truth" the Hebrews mean "righteousness".

Rejoiceth not in iniquity,.... Neither in his own, nor in others; but on the contrary is grieved for it; he mourns over his own iniquities, the corruption of his heart, the infirmities of his life, his secret sins, which none know but God and his own soul; he is greatly troubled at the profaneness and immorality of the men of the world, and the sins of professors cut him to the heart: nor does he rejoice in injustice, as the word used here may be rendered, in any unjust action or injury, that may be done to any, yea, even to an enemy; even as Christ, when Peter, in great zeal for him, drew his sword and cut off the ear of one of the high priest's servants, who was more busy than the rest in apprehending Christ, and showed more malignancy than others, was so far from rejoicing at it, that he was displeased with Peter for doing it, and was moved with so much compassion to that man, though his enemy, as to heal him: but rejoiceth in the truth; in the truth of the Gospel, and the success of it; such an one can do nothing against it, but for it, will buy it at any rate, but sell it upon no account whatever; and he rejoices greatly when he sees any walking in it, and agreeably to it; for truth, as it stands opposed to iniquity or unrighteousness, may signify an upright, holy, and righteous conversation, a conversation becoming the Gospel of Christ, which that teaches, and by which it is adorned; now a gracious soul desires this in itself, and delights to see it in others.

rejoiceth in the truth--rather, "rejoiceth with the truth." Exults not at the perpetration of iniquity (unrighteousness) by others (compare Genesis 9:22-23), but rejoices when the truth rejoices; sympathizes with it in its triumphs (2-John 1:4). See the opposite (2-Timothy 3:8), "Resist the truth." So "the truth" and "unrighteousness" are contrasted (Romans 2:8). "The truth" is the Gospel truth, the inseparable ally of love (Ephesians 4:15; 2-John 1:12). The false charity which compromises "the truth" by glossing over "iniquity" or unrighteousness is thus tacitly condemned (Proverbs 17:15).

Rejoiceth not in iniquity - Yea, weeps at either the sin or folly of even an enemy; takes no pleasure in hearing or in repeating it, but desires it may be forgotten for ever. But rejoiceth in the truth - Bringing forth its proper fruit, holiness of heart and life. Good in general is its glory and joy, wherever diffused in all the world.