John Calvin Commentary James 2:13

"For judgment [is] without mercy to him that hath showed no mercy: mercy glorieth against judgment." — James 2:13 (ASV)

For he shall have judgment. This is an application of the last verse to the subject at hand, which fully confirms the second explanation I have mentioned. For he shows that since we stand through God’s mercy alone, we ought to show that mercy to those whom the Lord Himself commends to us.

It is, indeed, a singular commendation of kindness and benevolence that God promises He will be merciful to us if we are so to our brethren. This is not because our mercy shown towards men, however great it may be, merits the mercy of God. Rather, it is because God would have those whom He has adopted—since He is a kind and indulgent Father to them—to bear and exhibit His image on the earth, according to the saying of Christ.

Be you merciful, as your heavenly Father is merciful (Matthew 5:7).

We must notice, on the other hand, that He could pronounce nothing more severe or dreadful against them than His judgment. Hence, it follows that all those are miserable and lost who do not flee to the asylum of pardon.

And mercy rejoiceth. As if he had said, “God’s mercy alone is what 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” in this passage as referring to a person, for men cannot properly be said to rejoice or glory against the judgment of God. But mercy itself, in a way, triumphs and alone reigns when the severity of judgment gives way. Though I do not deny that from this arises confidence in rejoicing; that is, when the faithful know that the wrath of God, in a way, yields to mercy, so that being relieved by the latter, they are not overwhelmed by the former.