Medieval thinkers schematized the three religions as Fortune, Nature and Grace

Evidence

William of Auvergne reports two interesting comparisons of the three revealed religions that were current in his own day among people reputed sapientes in mundo. One of these views distinguished Fortune, Nature and Grace. The religion of the Hebrews was that of Fortune, which the Jews might be said to worship, since their reason for holding their religion was that it brought them temporal prosperity. Muslim religion was the religion of Nature, because it contained few requirements; nature here meant corrupt nature, and Muslims indulged carnal delights for which they thirsted. The Christian religion was that of Grace. — Norman Daniel, Islam and the West, 1054

Categorization

• QUESTION: Where does this Fortune/Nature/Grace tripartite scheme come from originally, and does it trace to a classical or late-antique source?
• XREF: connects to: Medieval thinkers speculated about astrological causes of religious difference.