Life, Death, and God's Sovereignty

Theomorph, our resident atheist, has asked an astute question in a comment to yesterday’s post about Terri Schiavo.

"If suicide or murder are wrong because they contravene God’s alleged desires for the course of a life, how can you not apply the same reasoning to technological attempts to extend a life in the face of otherwise insurmountable difficulties? I.e., if a person would die without medical intervention, how is medical intervention also not a contravention of God’s apparent desires? If "rights come from God and God alone," then the right to live also comes from God and God alone, does it not? How does one ascertain when God has removed that right, beyond which point all human efforts to maintain life are in opposition to the will or desire of God?"

How do we reconcile God’s sovereignty with modern medicine? Are those who renounce medical and pharmaceutical technology in favor of healing by prayer actually right? How do we decide the will of God? When do life-saving techniques stop being appropriate efforts and start being contrary to God’s wishes?

What say you, Christian readers of my blog?