Horatius Bonar emphasizes the chilling effect of iniquity on love, as foretold in Matthew 24:12, warning that in the last days, love for God and one another will diminish significantly. He outlines how increasing sin leads to a decline in faith, truth, righteousness, and genuine religion, ultimately resulting in a coldness of heart towards God and fellow believers. Bonar stresses that love is the most vulnerable aspect of our spiritual lives, easily affected by the surrounding atmosphere of sin. He calls for vigilance against sin and encourages the nurturing of love, as it is essential for a vibrant faith. The sermon serves as a reminder of the importance of maintaining love amidst a world increasingly filled with lawlessness.

"Because iniquity shall abound, the love of many shall wax cold."—Matthew 24:12. This is to be specially true of the last days, so that, as our Lord elsewhere said, "When the Son of man cometh, shall he find faith on the earth?" here he may be supposed to be asking a similar question, When the Son of man cometh, shall he find love on the earth? But while this is to be fulfilled in the last days, it is not confined to these. Such is the tendency of every age, every church, every saint. In this present evil world the tendencies are all evil; downward, not upward. Increasing evil and decreasing good; this is the general statement. But our Lord's words are more special. It is of decreasing love that he speaks: "Thou hast left thy first love." Let us notice some of the things which decrease when sin increases. 1. As iniquity increases, faith decreases. Unbelief overflows like a deluge. One sin lets loose another. Faith withers down; dies out, like a flower in a desert. 2. As iniquity increases, truth decreases. For error is sin, and sin is error; so that truth and sin cannot co-exist. Sin expels truth, both from the heart and from the world; from the individual saint, and from the church at large. Darkness dispossesses light. 3. As iniquity increases, righteousness and holiness decrease. A man cannot be both holy and unholy; the encroachments of sin can leave no room for holiness at all. Inch by inch, iniquity creeps in and creeps along. 4. As iniquity increases, religion decreases. Sin drives religion out of the heart, out of the church, out of the world. With abounding iniquity prayer dies out, and praise, and zeal. The service of God becomes irksome; the form without the power is the first stage of the declension; and the second is the abandonment of both power and form. 5. As iniquity increases, delight in the things of God decreases. Sin soon shuts the Bible, and takes away all relish or appetite for it, except as a book of poetry or antiquity. Pleasure in sin cannot co-exist with pleasure in the Word of God, or the day of God, or any of the things of God. But the special thing of which our Lord predicts the decrease is love,—love to God, love to Himself love to one another. The atmosphere of sin is poisonous to everything sacred; but the thing which it first especially acts upon is love. It chokes this immediately. Hence the first thing noticed by our Lord in regard to Ephesus, was her leaving her first love. Love is the tenderest of all the plants of heaven, and the most easily affected by the deleterious or cold atmosphere of earth. The first step backward and downward is failure in love. A chill comes over us. Something intervenes between us and Christ, between us and our fellow-saints. We begin to grow cold, and then we freeze. This is specially to be the case in the last days, but the tendency is the same throughout the whole dispensation,—increasing sin, decreasing love. The Greek word for iniquity is "lawlessness" (η χνομιά); regardlessness of that law of which love is the fulfilling; assimilation to the great Antichrist, who is specially the lawless one (ό άνομος); and as the characteristic of this lawless one is hatred of Christ and of his church, so is every step in "iniquity" an advance to this great image of sin, this model of hell, Satan's truest representative. The evil predicted by our Lord is threefold. It is love (1) frozen out of the world by abounding iniquity; (2) frozen out of the church; (3) frozen out of the saint. A world without love, a church without love, a saint without love! It is not of a few, but of the multitude (the όι πολλοι), "the most," that this is affirmed. Coldheartedness will be all but universal; and even those who do love will love but little. Theirs will be but cold love,—half a heart given to Christ; less than half a heart given to the saints. Let us watch against sin,—all sin; tremble at its increase. Cherish the flame of love; for "if any man love not the Lord Jesus Christ he shall be anathema maranatha."