U2’s “Grace”

What is the best theological description of “grace” that you know of? For me, it’s the U2 song “Grace,” especially that remarkable line: “She travels outside of karma.” This line contains the whole gospel in nuce. It expresses the sheer strangeness and audacity of the gospel, the sheer gratuitousness of grace, and it does so in a way that is immediately intelligible within the contemporary cultural situation. The whole song is splendid; but I reckon this line in particular is a model of theological perfection.