Joseph Haroutunian (1904-68) is one of my favorite Edwards scholars. I enjoyed finding this quote in his 1932 book (though Robert Jenson believes "it might have been written yesterday" [America's Theologian: A Recommendation of Jonathan Edwards, 198]) Piety Versus Moralism: The Passing of the New England Theology (repr 1964), in a chapter entitled "Reform without Regeneration." He is explicating Edwards' understanding of the new birth, a conviction that, while central to the Great Awakening of the 1740s, waned in the generation immediately following his death (on which see also Haroutunian's "Jonathan Edwards: A Study in Godliness," Journal of Religion : 400-19).
The natural affections, being qualitatively different from the sense of divine glory, do not and cannot produce it. The 'natural man' may be a sensible and well-behaving person; he may follow the dictates of his conscience; he may even be affectionate toward his neighbors. But in all this he is guided merely by prudence and the natural affections, which are necessarily for self-preservation. Human depravity does not consist in a lack of these qualities. . . . [T]o be religious and to be moral are two different things. Morality is natural; religion is supernatural. The latter is based upon a 'new principle,' derived, not from nature, but from God. The sense of the divine is produced by the Divine, through the operation of the indwelling Spirit of holiness, introducing a 'new principle' and a new object of affection. (p. 45)
My dream is not that we reproduce the 1740s today. Spiritual revivification will look and smell and feel like the 21st century, not the 18th. Nevertheless I believe that at the heart of what must be recovered in the Church today, under God, if it is to be a united and happy force in the world, is the widespread recovery of the nature of true (i.e. supernatural) conversion, as happened, among other times in history, 250 years ago.