From “The Divine Conspiracy: Rediscovering Our Hidden Life In God” (Dallas Willard) (p. 111); on the parable of The Good Samaritan (Luke 10:25-37):
The story does not teach that we can have eternal life just by loving our neighbor. We cannot get away with that nice legalism either. . . . But in God’s order nothing can substitute for loving people. And we define who our neighbor is by our live. We make a neighbor of someone by caring for him or her. . . .
Jesus deftly rejects the question, “Who is my neighbor?” and substitutes the only question really relevant here: “To whom will I be a neighbor?” And he knows that we can only answer this question case by case as we got through our days. In the morning we cannot yet know who our neighbor will be that day. The condition of our hearts will determine who along our path turns out to be our neighbor, and our faith in God will largely determine who we have strength enough to make our neighbor.
(Emphasis added)