Leave it Piper to put things in perspective. Not only is this great stuff for diseases, but also for those that misunderstand calvinism and ask “Why evagelise if God has already chosen whom he will save?”
The logic of the Bible says: Act according to God’s “will of command,” not according to his “will of decree.” God’s “will of decree” is whatever comes to pass. “If the Lord wills, we will live and do this or that” (James 4:15). God’s “will of decree” ordained that his Son be betrayed (Luke 22:22), ridiculed (Isaiah 53:3), mocked (Luke 18:32), flogged (Matthew 20:19), forsaken (Matthew 26:31), pierced (John 19:37), and killed (Mark 9:31). But the Bible teaches us plainly that we should not betray, ridicule, mock, flog, forsake, pierce, or kill innocent people. That is God’s “will of command.” We do not look at the death of Jesus, clearly willed by God, and conclude that killing Jesus is good and that we should join the mockers.