The main point of Christian sexual morality is that human nature is designed. We need to live a certain way because we’re designed to live that way.” He said, “I can see design in an organ like the heart. Human nature—that’s a little too big for me.” “Then let’s start with the heart. Do you see how every part works together toward its purpose, its function?” “Sure. You’ve got nerves and valves and pumping chambers, all for moving blood.” “Right. If you think about the sexual powers instead of the heart,