Steve's Book on Revelation-Comment: Just a word of appreciation for Steve's teaching and his Revelation book. Uncleanness in Old vs New Testament: Can you clarify the difference between "uncleanness" in the Old Testament and its spiritual application in the New Testament? [2 Corinthians 6, 7:11] Isaac & Ishmael: Can you help me to understand the significance of Isaac & Ishmael? [Galatians 4:21-31].