Verse 1-11 — Here is a strict caution against all friendship and fellowship with idols and idolaters. Those who are in communion with God, must have no communication with the unfruitful works of darkness. Limiting the orders to destroy, to the nations here mentioned, plainly shows that after ages were not to draw this into a precedent. A proper understanding of the evil of sin, and of the mystery of a crucified Saviour, will enable us to perceive the justice of God in all his punishments, temporal and eternal. We must deal decidedly with our lusts that war against our souls; let us not show them any mercy, but mortify, and crucify, and utterly destroy them. Thousands in the world that now is, have been undone by ungodly marriages; for there is more likelihood that the good will be perverted, than that the bad will be converted. Those who, in choosing yoke-fellows, keep not within the bounds of a profession of religion, cannot promise themselves helps meet for them.
Verse 12-26 — We are in danger of having fellowship with the works of darkness if we take pleasure in fellowship with those who do such works. Whatever brings us into a snare, brings us under a curse. Let us be constant to our duty, and we cannot question the constancy of God's mercy. Diseases are God's servants; they go where he sends them, and do what he bids them. It is therefore good for the health of our bodies, thoroughly to mortify the sin of our souls; which is our rule of duty. Yet sin is never totally destroyed in this world; and it actually prevails in us much more than it would do, if we were watchful and diligent. In all this the Lord acts according to the counsel of his own will; but that counsel being hid from us, forms no excuse for our sloth and negligence, of which it is in no degree the cause. We must not think, that because the deliverance of the church, and the destruction of the enemies of the soul, are not done immediately, therefore they will never be done. God will do his own work in his own method and time; and we may be sure that they are always the best. Thus corruption is driven out of the hearts of believers by little and little. The work of sanctification is carried on gradually; but at length there will be a complete victory. Pride, security, and other sins that are common effects of prosperity, are enemies more dangerous than beasts of the field, and more apt to increase upon us.