James 2:13

13For he shall have judgment. This is an application of the last verse to the subject in hand, which confirms altogether the second explanation which I have mentioned: for he shews, that since we stand through God’s mercy alone, we ought to shew that to those whom the Lord himself commends to us. It is, indeed, a singular commendation of kindness and benevolence, that God promises that he will be merciful to us, if we be so to our brethren: not that our mercy, how ever great it may be, shewn towards men, merits the mercy of God; but that God would have those whom he has adopted, as he is to them a kind and an indulgent Father, to bear and exhibit his image on the earth, according to the saying of Christ,

“Be ye merciful, as your heavenly Father is merciful.”
(Matthew 5:7.)

We must notice, on the other hand, that he could denounce nothing on them more severe or more dreadful than the judgment of God. It hence follows, that all they are miserable and lost who flee not to the asylum of pardon.

And mercy rejoiceth. As though he had said, “God’s mercy alone is that which delivers us from the dread and terror of judgment.” he takes rejoicing or glorying in the sense of being victorious or triumphant; for the judgment of condemnation is suspended over the whole world, and nothing but mercy can bring relief.

Hard and forced is the explanation of those who regard mercy as put here for the person, for men cannot properly be said to rejoice or glory against the judgment of God; but mercy itself in a manner triumphs, and alone reigns when the severity of judgment gives way; though I do not deny but that hence arises confidence in rejoicing, that is, when the faithful know that the wrath of God in a manner yields to mercy, so that being relieved by the latter, they are not overwhelmed by the former.