Post Author: Bill Pratt

Christians claim that God is both merciful and that he is just, but how can both of these be true?  Doesn’t mercy cancel justice, or justice cancel mercy?

Thomas Aquinas, one of the greatest church fathers, addressed this very issue in his monumental work, Summa Theologica.  Thomas’s approach in Summa Theologica was to present an objection, and then answer the objection.  Here is the objection:

Further, mercy is a relaxation of justice. But God cannot remit what appertains to His justice. For it is said (2 Tim. 2:13): If we believe not, He continueth faithful: He cannot deny Himself. But He would deny Himself, as a gloss says, if He should deny His words. Therefore mercy is not becoming to God.

In other words, God is just and God cannot deny himself.  If God is just, and mercy is a relaxation of justice, then God cannot be merciful.  How does Thomas answer this objection?

God acts mercifully, not indeed by going against His justice, but by doing something more than justice; thus a man who pays another two hundred pieces of money, though owing him only one hundred, does nothing against justice, but acts liberally or mercifully. The case is the same with one who pardons an offence committed against him, for in remitting it he may be said to bestow a gift. Hence the Apostle calls remission a forgiving: “Forgive one another, as Christ has forgiven you” (Eph. 4:32). Hence it is clear that mercy does not destroy justice, but in a sense is the fulness thereof. And thus it is said: “Mercy exalteth itself above judgment” (Jas. 2:13).

Philosopher Peter Kreeft, commenting on Thomas’s words in his A Summa of the Summa, adds that

Mercy is expressed in forgiveness.  In the word “forgive” is the word “give.”  For forgiveness is not primarily an attitude or feeling, but a gift,  remitting of debt, and therefore it costs the giver something.  God’s forgiveness of human sin cost him dearly on Calvary.  Both justice and mercy were satisfied there.

Further building on the interaction of mercy and justice, Kreeft explains that

mercy, as a property of love, is more primordial than justice.  Justice [as God applies it to mankind] is finite, and proportioned to desert; love can be infinite.  Our very existence is due to love and generosity, not justice, for we were not even there to deserve anything, even existence, before God gave us the gift of existence.

In summary, mercy is more basic than justice, and mercy can therefore complete justice.  To be truly merciful is not to negate justice, but to fulfill it.  Nothing better illustrates this concept than what God did on the cross for mankind.