If the modern concept of altruism derives from the Christian concept of agape, the ultimate source of the concept is in the Christian understanding of God. Nygren contends that agape is only a human possibility at all because it is the divine reality. Human agape results from participation in the overflowing divine agape. Unselfish love of neighbor is inspired by and sustained through faith in the unselfish love of God. On this reading, God is the absolute altruist. Our existence is due ultimately to the overflowing generosity of God. Our continued existence is due to the persistence of that generosity in the redemption that reaffirms us in spite of our rejection and abuse of that generosity through sin.

Reservations about Nygren's total contrast between agape and eros extend beyond concern with the loss of the erotic dimension of human life, and the neglect of the mutuality of philia, to a questioning of the adequacy of this understanding of God exclusively in terms of agape. The total generosity of agape, on its own, may not represent the epitome of altruism. Although this vision sees the distinctiveness of God in terms of ultra-altruism, this altruism is possible only because God is characterized by an intrinsic self-sufficiency. The aseity of God constitutes the ontological basis of the character trait of love. The generosity of overflowing and undeserved agape is a reflection of the divine plenitude.