Original sentence: His book 'Letters From a Skeptic' (1995) contains much Hartshornian philosophy that was later expanded in the book God of the Possible (2000) in which he described his  view of God, or open theism, the view that the future is open and therefore known to God partly as a realm of possibilities
Edited sentence: His book 'Letters From a Skeptic' (1995) contains much Hartshornian philosophy that was later expanded in the book God of the Possible (2000) in which he described his post-evangelical view of God, or open theism, the view that the future is open and therefore known to God partly as a realm of possibilities