Q1. How does Job's vision of resurrection (Job 19:25-27) differ from the Jews' former understanding of death as Sheol? What is progressive revelation?
I believe Job's vision of resurrection was Divinely imparted to him by God...revelation knowledge. The Jews had not been given this revelation yet and so believed that when they died they went to Sheol (the grave) a deep, dark place without the Presence of God.
Progressive Revelation is, in essence, God's perogotive, to enlighten His people at any given time, to new understanding and depth of His Person and His Word.