Faith, which is nothing other than receiving, is a taut coil springing creatively into action for the common good. For believers know that since God has done enough for our salvation, we can never do enough for the good of the world. So we are justified by faith alone, but faith never stays alone; it strives to, it has to become active in love: 'faith alone is never alone' (Paul Althaus). There is no more liberating basis for ethics than the doctrine of justification of sinners by faith alone.
--Eberhard Jungel, Justification: The Heart of the Christian Faith (trans. J. F. Cayzer; T&T Clark 2001), 259