The motif of mercy is most prevalent in The Heart of the Matter when appearing as an attribute of God. The question of Scobie’s metaphysical state following his suicidal act is inextricably tied to God’s mercifulness. In Christian doctrine, God’s mercy is extended to save believers, even when they deserve to be punished. However, in religious thought, there are few crimes more worthy of punishment than suicide, or as Scobie calls it, the “unforgivable sin.” Father Rank’s suggestion that God might still forgive Scobie, despite what the Church says, is heretical according to orthodox Christianity. But the sublime and unknowable reality that is God and God’s mercy cannot, in Greene’s admittedly iconoclastic view, be understood through the Church. This is not to suggest that rules don’t matter in religion; it may simply be that they are not an exact representation of God’s justice or will.

Scobie feels an immense fatalistic weight. He thinks to himself, “[H]uman beings were condemned to consequences” (149). There is a theological determinism that underpins Scobie’s religious beliefs. In this light, mercy must also be understood as a matter of fate and free will. As in theodicy, Scobie struggles to reconcile a God that doesn’t love His creatures.