I like to study a passage until I can state the main idea in one sentence and then be able to break it down into sections of thoughts, or points, or however it seems to divide itself out. This helps me grasp the overall meaning of the passage and the flow of thought as I study through a book.
I would state the theme of John 8.21-30 as: Unless you believe that Jesus is the Son of Man/Son of God, you will die in your sins.
The passage seems to break down like this as Jesus points out the difference between himself and his listeners:
- His origin is different. He is from above, his listeners are from below
- His mission is different. He can save his listeners from dying in their sins, his listeners cannot do that.
- His father is different. His listeners have earthly fathers, Jesus is from above, he has God as his father