" Thus growth in love, growth in compassion, is the primary quality of life in the Spirit. It is also the primary criterion for distinguishing a genuine born-again experience from one that only appears to be one. It is the pragmatic test suggested by William James, quoting Jesus: “By their fruits you shall know them.” The fruit is love. Indeed, such fruit is the purpose of the Christian life. "

― Marcus J. Borg , The Heart of Christianity: Rediscovering a Life of Faith