Wolfhart Pannenberg, Systematic Theology, 473 pp, trans. G. W. Bromiley (Grand Rapids, Mich.: Eerdmans, 1991), 1:6/6/b, 5/3/b. I have explored the meaning of infinity which underlies the concept of eternity in Robert John Russell, "The God Who Infinitely Transcends Infinity: Insights from Cosmology and Mathematics Into the Greatness of God," in How Large is God? ed. John Marks Templeton and Robert L. Herrmann (Philadelphia: Templeton Foundation Press, 1997).