Romans 12:20

if thine enemy hunger, &c.--This is taken from Pro 25:21-22, which without doubt supplied the basis of those lofty precepts on that subject which form the culminating point of the Sermon on the Mount. in so doing thou shalt heap coals of fire on his head--As the heaping of "coals of fire" is in the Old Testament the figurative expression of divine vengeance (Psa 140:10; Psa 11:6, &c.), the true sense of these words seems to be, "That will be the most effectual vengeance--a vengeance under which he will be fain to bend" (So ALFORD, HODGE, &c.). Rom 12:21 confirms this.

The apostle, having at large cleared and confirmed the prime fundamental doctrines of Christianity, comes in the next place to press the principal duties. We mistake our religion if we look upon it only as a system of notions and a guide to speculation. No, it is a practical religion, that tends to the right ordering of the conversation. It is designed not only to inform our judgments, but to reform our hearts and lives. From the method of the apostle's writing in this, as in some other of the epistles (as from the management of the principal ministers of state in Christ's kingdom) the stewards of the mysteries of God may take direction how to divide the word of truth: not to press duty abstracted from privilege, nor privilege abstracted from duty; but let both go together, with a complicated design, they will greatly promote and befriend each other. The duties are drawn from the privileges, by way of inference. The foundation of Christian practice must be laid in Christian knowledge and faith. We must first understand how we receive Christ Jesus the Lord, and then we shall know the better how to walk in him. There is a great deal of duty prescribed in this chapter. The exhortations are short and pithy, briefly summing up what is good, and what the Lord our God in Christ requires of us. It is an abridgment of the Christian directory, an excellent collection of rules for the right ordering of the conversation, as becomes the gospel. It is joined to the foregoing discourse by the word "therefore." It is the practical application of doctrinal truths that is the life of preaching. He had been discoursing at large of justification by faith, and of the riches of free grace, and the pledges and assurances we have of the glory that is to be revealed. Hence carnal libertines wou…

12:20-21 A simple act of Christian kindness can often bring a hostile person to repentance before God and restore fellowship between people.