Next week I am guest blogging every day on Zondervan’s koinonia blog (so stop by and make a comment if you’d like). I just composed this one this morning, and before I send it in I thought I’d invite any helpful feedback that you might have. Here it is.
I want to try out a thesis that may be controversial. I believe that, thanks to common grace, non-Christians throughout the world love their children, care for ailing parents and spouses, and sometimes even sacrifice their lives for strangers (e.g., the New York firefighters who on 9/11 ran up the stairs of the World Trade Center while everyone else was fleeing down).
But non-Christians perform these acts of love despite rather than because of their worldview. I propose that the Christian faith alone supplies the rationale for altruistic love. When Christians love others they are acting in sync with their ultimate beliefs. When non-Christians love others they are behaving better than their beliefs allow. They are borrowing from the Christian worldview, acting as if the Christian faith is true.
I don’t have space to address every non-Christian worldview, but I’ll briefly examine Christianity’s two largest competitors in order to demonstrate how this might go.
1. Secular humanism: Alvin Plantinga observes that social scientists committed to philosophical naturalism (there is no God, just nature) believe that each person seeks his own interest in a cosmic survival of the fittest. So how to explain why some people sacrificially love others? According to these scientists, altruistic people suffer from “docility” (they do what others tell them) and “bounded rationality” (they are dumb). Should these scientists themselves ever genuinely love—and God help their families if they do not—they have by their own standard become stupid wimps.
2. Islam: Muslims often show kindness to others. But Islam is a performance-based religion grounded in fear: do the best you can and hope that it will be enough for Allah to accept you. While this religious system may encourage Muslims to do many good deeds, it cannot turn them into lovers. Frightened people are too focused on themselves to put others first. When Muslims genuinely love others, they are acting inconsistently with their religious beliefs.
What makes the Christian faith a superior ground for altruistic love? Two things.
1. The Christian Trinity supplies the ontological ground and model for love.
Christians believe that the triune God is a community of self-giving lovers: a Father, Son, and Holy Spirit who have eternally set aside what might be in their own interests to serve the other. When Jesus prayed in Gethsemane, “Not my will, but yours be done” (Luke 22:42), he was not declaring anything new, but was simply continuing the submission that the perfect Son always gave to the Father. Likewise, the Spirit obeys both the Father and the Son (John 14:26; 15:26), and they in turn watch his back. Jesus said that every sin will be forgiven except one: whoever slanders the Spirit will not be forgiven in this age or in the age to come (Matthew 12:31-32).
If we are created in the image of this triune, self-giving God, then it should be the most natural thing in the world for us to love our neighbor. Just as our triune God of love flourishes as he loves the other—first within the Godhead and then we his creatures, so we are wired to thrive as we give ourselves away. If God is life and God is love, then we are most fully alive when we love like God.
2. The Christian story of salvation supplies the motivation for love.
Every non-Christian religion that offers personal salvation states that this salvation is obtained by doing good works. But if we are doing good works in order to earn our salvation, then these works would seem to be tinged by selfishness. They are not entirely altruistic.
In contrast, Christians love their neighbor not to earn God’s love but because they have already received that love. John writes that “We love because he first loved us” (1 John 4:19). As Martin Luther explained in his classic work, The Freedom of a Christian, Christians who know that they are secure in Christ are free to selflessly serve their neighbor. He wrote:
Although I am an unworthy and condemned man, my God has given me in Christ all the riches of righteousness and salvation without any merit on my part, out of pure, free mercy, so that from now on I need nothing except faith which believes that it is true. Why should I not therefore freely, joyfully, with all my heart, and with an eager will do all things which I know are pleasing and acceptable to such a Father who has overwhelmed me with his inestimable riches? I will therefore give myself as a Christ to my neighbor, just as Christ offered himself to me; I will do nothing in this life except what I see is necessary, profitable, and salutary to my neighbor, since through faith I have an abundance of all good things in Christ.
According to question two of the Heidelberg Catechism, when we understand “how great my sin and misery are,” only then can we appreciate “how I am set free from all my sins and misery,” which then automatically leads us to wonder “how I am to thank God for such deliverance.” And thankful Christians devote themselves to good works, seeking to please God by loving their neighbor. Grace (charis) produces gratitude (eucharistia) which produces works of love. Can there be any other logical ground for altruism?
It is increasingly popular today to suggest that fixating on the specific, historic doctrines of the Christian faith supplies an obstacle to loving others. How are we going to demonstrate the inclusive love of Jesus if we make others believe like us before we welcome them into the kingdom of God?
Against this rising tide of compassionate inclusivism, I propose that the historic doctrines of the Christian faith—specifically the doctrine of the Trinity and the story of salvation—supply the only logical ground for genuinely loving others. A healthy focus on these doctrines will yield more love, not less, for Christians who truly believe in them will be appropriately motivated to sacrificially love their neighbor.
 See Herbert Simon, “A Mechanism for Social Selection and Successful Altruism,” Science 250 (December, 1990): 1665-68, as cited in Alvin Plantinga’s lecture “Science and Christian Belief: Conflict or Concord?”, at The January Series of Calvin College (Grand Rapids, MI), January 18, 2005.
 Two religions, Amida Buddhism and the Ramanuja and Madhva forms of Hinduism, teach a form of grace (though not the robust kind found in Christianity that requires the death of a sinless substitute). But neither offer salvation. Instead, they hope for the termination of personal existence, where individuals are dissolved into the oneness of the universe. Their free offer of personal extinction sounds more like death than anything that might count as grace.
 Luther, “The Freedom of a Christian,” in Martin Luther’s Basic Theological Writings, 2nd ed., ed. Timothy F. Lull (Minneapolis: Fortress Press, 2005), 406 (italics mine).