Dr. John Gordon, a Christian IVF doctor, was co-director of a large fertility clinic when he started to have doubts about his profession. He was troubled over helping create surplus embryos, which would often languish in storage or be discarded. With the expansion of genetic testing, couples could choose the sex of their baby. They could screen out painful or fatal diseases, but also milder impairments like hearing loss. “What are children?” he asked recently. “I mean, are they a gift from the